The main sore issues that Poles are submiting to Lithuanian government:
1. The refusal to acknowledge the Polish spelling of Polish minority`s surnames and names of streets and settlements.
2. The refusal to solve the problem with land/property ownership.
3. The obstruction over the Możejki oil refinery owned by Poles who bought it for hard cash to save Lithuania from Russian domination.
Actually I would say that you are wrong on some issues, though overall maybe you are right ;)
Ad 1. I agree that their stance toward this in fact small letter issue is silly. In fact not only Poles have a problem with that, some anonimous Dutch story:
"Naming is not just very personal, but one of the most difficult bureaucratic things around. Too bad this does not only concern Poles or Lithuanian Poles.
I am Dutch and married a Lithuanian woman. Of course, we had to register our marriage in Vilnius, and report the documents back because of name-change regulation.
I was lucky, because my name does not contain one of the letters that 'do not exist in the Lithuanian alphabet'. Would that be the case, the civil servant would change it as he/she sees fit. Getting it back to the Netherlands and explaining that it is REALLY me (and more importantly: that my wife REALLY changed her name to MY name) is something that is downright Kafkaesque sadism. So actually, it is a big issue impacting the lives of everyone getting involved in this."
Ad 2. Taking into account unresolved issues regarding reprivatization in Poland:
"First remove the beam from your own eye, and then you will see clearly enough to remove the speck from your brother's eye."... but on the other hand it is politics not the justice court
Ad 3. Saving Lithuanians from Russian dominations was just a side effect of a main goal which was keeping quasi-monopoly of Orlen in Poland, what is not good thing from mine as a consumer point of view...
As for saving their asses in last centuries it is not so simple... Actually it is some at least half true in their complaing about occupation. Equality in Commonwealth ended in 1569 when they've lost at the same time independence and a lot of land. It was a union on Polish terms, many of Lithuanian nobles opposed it openly. Maybe if they keeped much of independence and ruthenian lands they would managed with pressure from Duchy of Moscow just fine. At least that is how they see it.
As for current matters I would say that this letter issue is just an excuse. Main issue is Orlen and Możejki. Orlen is big and influential state company and they must cut the losses. They didn't manage to deal with Lithuania on their own so they called gov. help...
On the side note, observing this seemingly small issues with Lithuania makes me wonder if it is not the way Russia sees Polish small issues... Maybe we should be more sensitive in our judgments regarding small Lithuania (once a superpower in the region)? Or maybe they just run out our sensitivity? I'm not sure