Here goes:
Every now and then when I do a thumbs up/karma + it seems to "not actually give" the vote. When I initially click to vote, it shows that I did. But when I go back on the page later it would still show the option to vote on the user's post, and would have no indication that I previously voted on the comment.
Happens around ~80% of the time in the comments and ~30% in the forums.
I have tried this on multiple browsers on multiple computers and has not been solved.
Voting a second time doesn't work, so don't tell me to do that herp derp.
If this has been addressed before then…whatever. I really don't want to look around the forums to find if this has been posted or not. If anything, it shows this is happening to more than one user.