Found non-frame during stack squeezing...

[Simon Marlow]

> When I build CVS HEAD with RTS debugging I sometimes get, at 
> exit time:
> 
> ghc-5.03: fatal error: Found non-frame during stack squeezing 
> at 0x504797a0 (prev frame was 0x504797a0)

I've seen this a couple of times, but don't have a repeatable example.
If anyone manages to nail one down, please could you send it to the
list?

Cheers,
	Simon