A few months ago, because of the mob feel that voting was starting to have now that the site has grown so big, I started experimenting with thresholds for which votes got counted (<a href="http://news.ycombinator.com/item?id=871202" rel="nofollow">http://news.ycombinator.com/item?id=871202</a>). The best test I could think of was the average score of a user's recent comments, so I used that.  Currently the threshold is 2.  The reason your votes stopped counting is that you dropped just below that.
Your average is currently 1.88.  (Ironically, it's much higher now because of the comments on this thread, but comment averages are calculated asynchronously, so there will be a lag before yours is recalculated.)<p>I'm probably going to do away with the display of point totals on comments entirely, because thresholds haven't fixed the problem.  In that case I'll just use points internally, e.g. to sort threads, and then I'll probably go back to counting most votes.<p>Edit: Since I was planning to toss the threshold when I stopped displaying comment scores, I just reset it to 1.  Also, since users asked to see their avg comment scores in their profile pages, I just added that.