Some V1000-based video cards are known to lock up the computer if you have write-combine activated. Disabling it removes the problem. Look for settings in the motherboards BIOS and disable ALL settings that has to do with write-combine (usually called USWC or just WC for short).
15 bits per pixel is only supported on V1000-based cards due to hardware limitations on V2x00 chipsets.
If you have problems with hardware cursor use the "sw_cursor" option to revert back to software cursor.
This is essentially a port of XFree86 3.3.x driver to the new XFree86 4.0 API, and thus we have put most of effort in making a working driver with the most basic features. Support for multi-head support and acceleration are next on the list of features to be included.