buglet with ctrl-C and reading stdin

Hi,

On my recently compiled-from-source GHC-6.4, I hit Ctrl-C while my
program was reading stdin, which earned me an "internal error: main
thread has been GC'd".  Which I now am dutifully reporting, just in
case.  Let me know if more information is required.

-kzm
-- 
If I haven't seen further, it is by standing in the footprints of giants