Ok, this is a pretty old bug at this point... but if one has doshaders, doindexbuffers, dovertexbuffers, and rglow on, and loads a total of 6+ different sectors they get a fps hit which looks like:
http://fuller.mit.edu/alan/vendetta/fpsGlitchBefore.gif
then after restarting the client look it looks like:
http://fuller.mit.edu/alan/vendetta/fpsGlitchAfter.gif

As far as I know this only happens with OS X machines, with ATI rglow capable graphics cards, while "dovertexbuffers" is turned on.

Is there any chance this is going to be fixed before Vendetta is released?

I really do wish I knew why that happens. I would love to fix it but don't know what's going on.

It's not just a Radeon issue. It also happens on my 12-inch PowerBook, which has an nVidia FX Go5200 (32MB). I'd really really really love to see this bug be squashed before final release. If it's something that can't be fixed or is given lowest priority... I'm not too sure I'll be able to continue playing. This is currently the best game I've ever played, hands down. And heck, it's just a test version. But the crippling performance can be too much sometimes.

=(