I might point out, from a quick browse of your recent posts that the reason for the most recent down vote was most likely as a result of posting in a solved thread with a new question.
Generally, if you have a new and unique question it gets a new thread, if your question is "solved" by someone else's post's resolution then it gets no thread at all. Resurrecting someone else's solved thread to start your own question is generally looked down upon.
As mentioned above, however, if you didn't get reputation loss from it, it really doesn't affect you other than as a reminder that you perhaps didn't do something in the accepted way, which is kind of the point of the voting system around here last I checked :)