Please, could anyone tell me why can't I render in my computer with blender? I'm running linux in a Pentium IV with an ATI Radeon 7500. When I try to render anything, the following message is shown:

blender: radeon_vtxfmt.c:1057: radeonVtxfmtUnbindContext: Assertion 'vb.context == ctx' failed

Thanks for your help.