slow response in fullscreen mode

[ametamorphosis]

I am experiencing a strange problem with my game.
I notice that my game runs faster in windowed mode than it does in full screen. I am running version 2.5 on a 500mhz amd k6/2 with a voodoo banshee 16mb card and 300+ megs of ram. Does anyone have any suggestions on how i can improve the animation speed in fullscreen? I would much prefer running the game fullscreen versus windowed. The problem seems even stranger since the documentation suggests that fullscreen runs much faster than windowed.

(the speed i am refering to is in the tactical mode when moving units)

thanks in advance