Hey, I was having the same problem this morning and came here to see if anyone had found anything better than "align to whole integers" since that didn't really work for me last time. But low and behold I went back and tried it and it worked!

Here is what I did. I have text, converted to symbols, converted to buttons on the main timeline. I did some tests and found that the only variable that mattered was Y. It didn't matter what X was. So I went into the button and aligned my symbol to a whole integer (ie. 9.0 not 9.2). Then I came back to the main timeline and aligned the button as well to a whole integer. And it works.

I know it gets more comlicated when you start burrying text in movie clips, but this did in fact work. I think last time I tried it I didn't go into the symbol level as well as button level. Now if we could only get the flash guys to fix this bug!

PippyLu