This is fixed in upstream CVS. It is due to the 4.2 version of the
Savage driver mis-detecting the video memory size.
A workaround is to set the size in your XF86Config-4 explicitly using
the VideoRam keyword. A proper solution is to remove the code that
(mistakenly) probes for the memory size using the VESA BIOS in
SavagePreInit in savage_driver.c.
Good luck,
Juliusz