[Wine] Very low FPS in Wine/Ubuntu vs WindowsXP

[M60HAKAN]

New on Linux and Wine. I like most of what I see. Here is one problem I don't understand. I run dualboot Windows XP / Ubuntu 10.04 LTS Lucid Lynx with Wine 1.3.6. Graphics - GeForce 9500 GT with Linux driver 195.36.24

Tested World of Warcraft and compared framerates in XP vs Ubuntu/Wine. With all parameters the same (same Config.wtf file with OpenGL set), same in-game options, same character, same place (Dalaran) same movements.

Result:
XP - 35-40 fps
Ubuntu10/Wine 12 -20 fps   :( 

No other "tweaks" than OpenGL. The easier adjustments and "tweaks" suggested in older threads here and in other forums had no impact on fps.

Is this as you should expect? Any suggestions on what to do to get fps at least a bit closer to XP?