So, this really is a question that goes over 2000 years of history, and even a very short answer has to divide that up a lot.

First - early on. The old testament was translated into Koine greek already well before the birth of Christianity, with a lot of evidence that it was the version of the bible that was quoted by the authors of the New Testament. The books of the New Testament were translated also into Syriac and Coptic, very early, as well as into Hebrew, all well before the establishment of a serious church hierarchy or power structure - i.e. it was a decentralized process.

Right towards the end of this period we have the translation of the bible into Gothic (3rd century) and then immediately following the proclamation of Christianity as the religion of the empire (380AD) Jerome was asked (in 382AD) to do a translation into the language of the empire, Latin. His wasn't the first, but it was pretty good.

Now empires have languages. One way of looking at this is in the context of another language, Russian. Pushkin, a strong supporter of the early Russian Empire, created a large body of literature that became the de facto foundation of the modern Russian literary language. Russia was spread across the empire, then became the language of the USSR, and now there is a bloody war being fought with at least lip-service being given to the idea of protecting the language rights of this language. A linguistic elite is going to some lengths to defend their oral/written culture from being replaced by "inferior" or "vulgar" languages. In some respect, the church's connection to government led to the language being given some importance.

Outside of this sphere, Amharic was translated at least by the 6th century, gospels into Irish in the 7th century, but for a long time after this the rise of vernacular translations wasn't a big deal in the western church as literacy was still largely Latin based. For example, many of the French spelling conventions we see today such as the use of X in various word final positions stem from Latin orthographic conventions and the way that French scribes annotated Latin for readability in French. For example, Old French is roughly dated as being between the 8th and 12th centuries - before this Latin was still Latin in the way that Modern Standard Arabic is Arabic for millions of people.

The first major incident connected to this that comes to my mind is the birth of the Waldensian movement. Peter Waldo started a group called the Poor of Lyons, teaching lay preaching, voluntary poverty, a strict adherence to scripture, and practicing the use of vernacular scriptures. In 1179 Waldo presented his beliefs, including the use of vernacular scripture, to Pope Alexander III. Later on that year, the third Lateran Council rejected these teachings. This is the first really clear time I know of (but there may have been others?) where the church officially took a stance against non-vulgate versions of scripture. Looking at the context, this is a translation into Arpitan - Franco-Provencal, definitely a language that is seen by educated people as being the domain of the uneducated. ALSO - language here was immediately tied into threats to power (lay preaching) and to a movement that was eventually labeled heretical. Within thirty years they were being burnt at the stake, and the relations continued in the same vein for several hundred years. Since one of the ways of identifying a Waldensian was that they often had translated scripture on their person, this can't have helped movements to translate into vernaculars.

So the bible was translated into French in the context of a heretical movement, it was then translated into Czech leading in part to the rapid growth of the Hussites, then a few short years later Wycliff and his fellow translators translated the bible into English contributing to/causing the Lollard movement, another movement called a heresy, and you can see the trend. Bible translation caused problems. None bigger than Martin Luther's translation roughly a century later leading to the protestant reformation.

The challenge of dealing with this for the church is that when bibles come out as the symbols of anti-clerical movements, it's hard to reclaim the symbol. The "extra-biblical" meaning of the bible is there already and has to be dealt with.

One way around this is to provide a "sanctioned" version with a different cultural meaning, so there were the Coverdale bibles in English and eventually the KJV, both of which were heavily influenced by Tyndale but didn't have the same anti-establishment message (and I'm not speaking of what was in them - they were all decent translations - I'm speaking of the context of their existence). Similarly in French official versions were translated, but the church eventually did take some type of a stand.

The Index Librorum Prohibitorum notes from the council of Trent in 1562 outlawed the writings of all reformers regardless of topic - including their bible translations. It also stated:

"Since experience teaches that if the reading of the Bible in the vernacular is permitted to all without distinction more harm than good results because of the audacity of men, the judgment of the bishop and inquisitor should be decisive with respect to vernacular translations.

-- as well as a lot of other things on the topic.

For me, i find the reasons given to be pretty important - the idea that the laity are naturally audacious and can't be trusted with the truth. In other words, the reason for being against vernacular scriptures was not because of the importance of the Latin (though as I've suggested, at times that had to have played a role) but rather it was because the educated class didnt' trust the uneducated to read things in ways that would be "right" (i.e. as I understand it, support the status quo). And given the widespread revolts among lower classes that seemed to result as a result of these translations (see Hussites, Lollards, Waldenses, 100 years war) they weren't entirely wrong about it being a threat to them.

Now here's the hard part of this answer. I'm a protestant Christian Anarchist from an ethnic minority, and heavily invested in resistance against all imposed authority structures, so there's only one answer I can give you to your question - "Absolutely!" of course this was tied in to protecting the authority of the Church system. But that's just the way I read history - it's like asking a Marxist if the rise of peasant revolts is connected to a class struggle - that's just the lens they use to view history. But in this case, I think even if I weren't this obviously biased, I'd still reach this conclusion.

I wouldn't, however, state it the way you did in your last sentence - "discover something inconvenient about the Bible". To my understanding it wasn't about hiding the secret truths, rather it was about maintaining the power of interpretation where it belonged - to people who had the right ideas. This tied in with a little bit of cultural chauvinism (Vulgate Version Only!) plus the historical connections between "vulgar" translations and resistance movements from the 10th through the 16th centuries, meant that my elders still weren't allowed to read the bible in English in their lifetimes.