Trouble when switch consoles with S3 Trio 64V+

hello,

i was quite pleased when i heard that XFree 4.2 supported the S3 Trio 64V+ 
graphics card (for antialiasing :-)).

i recently upgraded to Mandrake 9.0 which comes with XFree 4.2.1.
it works perfectly with S3 Trio 64V+ and my "Plug & Play" IBM P50 Monitor but 
if i switch VCs (CTRL+ALT+F1) and then back to X (CTRL+ALT+F7), the screen is 
now drawn in the bottom right hand corner of the screen (the rest is black).  
if i adjust my monitor settings to move the image to the left and up, i can 
see that it's not actually drawing the entire screen, just the top-left of it 
(but drawing it in the bottom-right, confusing I know).

this setup works perfectly with XFree 3.3.6 (but not with IBM P50 as the 
setting, I have to choose a different refresh rate otherwise there is this 
terrible flickering when I click anywhere).

please tell me what i have to change so that i can switch out of X and back in 
without X displaying everything in the bottom-right? refresh rate? bug?
i would really like to stop using the 3.3.6 branch.

please help!

thanks,
pesarif