I think those votes were mainly because you replied about 6 times in your own thread but basically didn't say anything much (your signature is longer than most of your posts in that thread).

I appreciate "thank you" nodes, and don't much mind nodes that are short, but I think 6 of them in one thread is getting close to the point of wasting time. And there are monks who dislike all "thank you" nodes enough to downvote them - though I don't see the point of that.

Also, practically any node complaining about votes (or even asking about negative votes) will end up with a negative rep.

update: I forgot to mention something that is quite obvious, but I think people forget sometimes: when you post a node with little information in it (like a thank you node), people usually won't find it worth an upvote, even if they appreciate the sentiment, so it'll only take a few downvote to give it a negative score.

In other words, a negative score of -1 .. -4 or so usually indicates a node with little or no information in it, and you probably shouldn't worry too much about it, while -10 or less indicates either a troll, or some really impopular point of view (the latter usually happens in perlmonks discussion, where people tend to vote according to their viewpoint, not according to informational value - I guess that's partly what the discussion category is for).