Bitcoin version 0.8.1-beta
Qt version 4.8.3

Screenshot:

http://www.freeimagehosting.nl/pics/44408cb76129be8e0813ed1286be3f86.png

Background:

I have used this Bitcoin client for a while. The configuration was initialized under Windows XP, and later on transferred to a Windows 7 machine. It has worked for several months swithout any notable problems -- with the only exception of it sometimes not including a "mined" transaction into my free balance immediately as it matures (instead it needs to be restarted).

Today, about 4 hours after receiving a "mined" transaction, it then crashed telling:

Assertion failed!
File: src/main.cpp
Line: 1127
Expression: pindexFirst

After restarting, it appears to have recovered fully.