Right click on desktop->properties
Settings-Tab
Advanced
From there on the dialog is driver dependent. Because I don't have such a Intel gfxcard available atm I can't exactly tell you what buttons are there and which exactly you have to click.
There has to be some Options for OpenGL. E.g in a tab or combobox or something.
Google showed me this page
http://www.neowin.net/forum/lofiversion/in...hp/t250385.html. That guy writes down the options he has in his display properties. Look for a part of that dialog that has options like that.
Then change "Flipping Policy" from Flip to Blit. Click Ok a few times until every dialog is closed. That should do it.

Btw. it's not only Walkover that has problems with these Intel chips. Here
http://ryzom.com/forum/printthread.php?t=6235&pp=50 a few guys complain about problem in Ryzom and KOTOR. Someone notes that he fixed the problems he had when switching from Flipping to Bliting. The last poor soul on that thread figured out that his problems were solved when he played in window mode instead of fullscreen. Guess what? Flipping only works in fullscreen mode, so basically he forced his gfxcard to use blitting by running the games in window mode.

And, note that my complaining about those intel drivers is already 6 months ago. Maybe there are new drivers out now that correct the problem and flipping works ok. I don't know, but you might want to give it a try and download the newest drivers from intel.