I was completing a mission - Facility T-H 751 Patrol, and saw several interesting "bugs" or issues.
At the very end of the cave there was an issue where some of the cave did not show up until you fully entered it. It also caused some weird issues with the characters. (Note: This issue went away when the camera went past entrance).
http://img338.imageshack.us/i/screenshot2010031911373.jpg/http://img192.imageshack.us/i/screenshot2010031911370.jpg/http://img403.imageshack.us/i/screenshot2010031911370.jpg/
Also during this mission there was a lighting issue with some of the weapon effects.
http://img179.imageshack.us/i/screenshot2010031911333.jpg/
(This effect is the only effect that caused it, I think...) This effect is produced by the Disruptor Pulse Rifle with the "Pulse Wave Setting".
http://img708.imageshack.us/i/screenshot2010031911304.jpg/
Comments
The second part (floor weirdness) is much more interesting. I made a post earlier in the 'Gameplay Bugs' forum about this exact issue (albeit with a different weapon). Seems like I'm not the only one that this has been happening to, meaning that it's more likely to be a bug than rendering issues clientside.