Intel GMA 500 seems to report FVFCaps 3DFVFCAPS_DONOTSTRIPELEMENTS as 'No', but it should report it as 'Yes'. Other Intel GPUs seem to report it right (Yes). Stripped formats do not seem to work with any Intel GPU. When trying to use stripped format vertices, everything renders bad in GMA 500. The same vertex format works fine with ATI/AMD GPUs.
Why does not Intel support element stripping by the way? Intel GPUs are slow already and we are forced write extra stuff in the GPU which are not needed in application, making it yet slower.