vesa.c, near line 1166:
if (pScrn->bitsPerPixel == 8 && pVesa->vbeInfo->Capabilities & 0x01 &&
!(data->data->MemoryModel & 0x6 || data->data->MemoryModel & 0x7))
Condition (data->data->MemoryModel & 0x6 || data->data->MemoryModel & 0x7) is incorrect. All 8-bit palette modes I've seen (vmware, via cle266, ati) comes with MemoryModel == 0x04, condition fails and default 6bit DAC paletter format left unchnged.
(data->data->MemoryModel == 0x6 || data->data->MemoryModel == 0x7) work for me.
Sorry about the phenomenal bug spam, guys. Adding xorg-team@ to the QA contact so bugs don't get lost in future.
Fixed in git, thanks!