it means you have temoral anti-aliasing on. Temporal anti-aliasing is some new thing that ati just started doing a few driver sets ago where they use v-sync along with aa to try and emulate higher aa levels, ie 2x aa will look like 4x aa and so on. To disable it just open up the ati control panel, hit the 3d tab, and click on the custom button, there should be a box in there that says temp aa, uncheck it and that should do it.