latest beta + MinGW 3.1.0-1 = minor fix needed

Some thoughts:
The first suggested fix seems to be forbidden during code freeze 
(might break other platforms, doesn't it?), the second one puts one 
more OS dependence into the sources.

The neither fix affects any platform except for Win32 - and that's the 
one we're fixing ;) - it's inside #ifdef Win32 - so I hope no other 
platform sets that define ;). On Win32 gcc int = long so in fact 
nothing should change - except for the error that would go away.

Simon