fx4600 + direct3d 9,0 driver problem

[max montana]

hi, i have a dell t7400 workstation with an nvidia fx 4600 graphic card. until now i used the open gl drivers. today i installed the newest drivers from the dell homepage for the graphic card and switched to direct3d 9.0 driver. i am very happy with the performance of the direct3d driver but face a peoblem. in edit mesh i can only see selected parts when i work in vertex mode. in all other modes i can´t see a selection. it only gets visible, when i make a selection(which is invisible), delete and undo, then the selected areas are marked. this happens in perspective view, camera view and all orthogonal windows.
tried F2 to make the selection visible, but no success.
would be very thankfull for suggestions

[max montana]

tested it in 2 other scenes and everything was fine. the problematic one is a scene where i have dosch cars 2006 into. really don´t know why only here this problem occurs.

[RErender]

You might try resetting the x-form on the bad geometry

[max montana]

thanks for your reply rerender. x-form helped on the first car, on the next one additionally i had to delete all edit mesh from the modifier stack and make a new edit mesh... strange to me is that i didn´t have this problem until i switched from opengl to direct3d, what has the modifier stack to do with that?
and should i be prepared to face more problems like this, when i work on with the direct3d driver?

[max montana]

one more problem occurs in that scene. i can use an edit mesh modifier only once on one object. when i finish the modifier and later want to activate the edit mesh modifier again, i cant make a selection - out of in vertex mode. the only way to handle this is, to delete the last edit mesh mod. from the modifier stack (then i loose also the modifications) and make a new edit mesh mod....
what´s the matter, never occured to me before.

[RErender]

I run the maxtreme driver from NVidia and do not have any issues, I also run the NVidia quadro drivers on my Dell not the ones from Dell, you might give them a try.