So the problem is that you're using an SiS chipset that isn't supported by that version of agpgart. If you think it works just like all the other SiS chipsets (which is often, but not always, the case), then you can edit /etc/modules.conf and add a line that looks like options agpgart agp_try_unsupported=1, save and exit, and run /sbin/depmod -a (this will get rid of a warning that modules.conf is more recent than the module dependency file). Then try it again, and see if it works.
Done that, simply get a blank screen again. When I check my logs I see the same errors as above.
Tomorrow or so I'll try
to update my kernel...