you turned it off globally? or specificly for Minecraft.exe?
post a picture of your current settings in the nvidia control panel for applications
If only I was on my computer, would be much easier to pinpoint the issue
also if you have nvidia inspector, you can also force aa off through there too
just on minecraft.exe, i'll try globally next
edit:
an idea proposal:
I heard at some point the owner was thinking of adding Towny. Well, if that mod were to be added, I think that PvP should be enabled so that players can create their own towns/factions/kingdoms and then declare war on others' towns/factions/kingdoms.
a war declaration would mean that the two players in charge of each faction would organize battles between the two factions, so players can duke it out in a good ol' round of PvP action.
"but blazer, what if the opposing town/kingdom/faction doesn't want to do PvP because they stink at it, or just want to be passive!?"
well the answer is simple, my good friend, the person that the declaration against can simply deny the declaration and continue on their merry way. should the leader of the town/kingdom/faction accept the declaration, but have members who do not want to participate, then they will not be forced to participate.
simple. fun. let's do it, huh?