Bookshelf 2K won't run

Problem: Access violation when opening Bookshelf. Exception number: c0000005
Worked fine a few days ago. Rebooting no help. The only installations done
recently were Firefox, Opera, Flash and Shockwave updates.

Any idea ideas as to possible cause?

Code w/fault (dr.watson):
012bbfcd 8d79fd lea edi,[ecx+0xfd] ds:00a99ee7=????????
012bbfd0 eb03 jmp 012c4cd5
012bbfd2 8d79fc lea edi,[ecx+0xfc] ds:00a99ee7=????????
012bbfd5 8b4c240c mov ecx,[esp+0xc] ss:00bc85e7=????????
012bbfd9 f7c103000000 test ecx,0x3
012bbfdf 741d jz 012c49fe
FAULT ->012bbfe1 8a11 mov dl,[ecx] ds:00000001=??
012bbfe3 83c101 add ecx,0x1
012bbfe6 84d2 test dl,dl
012bbfe8 7466 jz 012c4850
012bbfea 8817 mov [edi],dl ds:0132cb42=00
012bbfec 83c701 add edi,0x1

Thx,
nf