I'm running the latest Ubuntu on my laptop (9.04 I believe) and I've noticed when I run VO with my graphics set on medium or high (via the preferences) the game window likes to blink a lot. When I say blink I mean there's some kind of graphic issue going on where it flashes the desktop, then goes back to the game. This is fixed by turning the extra graphics in Ubuntu down, but I thought I'd report this for future reference. Not really a huge game-crushing bug, but something nonetheless.

"Extra graphics"? You mean "Desktop Effects" in GNOME? If so, you should disable those alltogether to play VO (or any 3D game for that matter).