Hey,
 
> I hope you are linking against the debug boost libraries. I have
> noticed such problems if you use boost release built libraries with
> debug build of your application.

Yes - i did. Our better "it did". Boost is linking automaticly because
auf the _DEBUG Macro. During compilation with the Macro BOOST_LIB_DIAGNOSTIC
set, i got the following:

1>Linking to lib file: boost_thread-vc90-mt-gd-1_44.lib
1>Linking to lib file: libboost_date_time-vc90-mt-gd-1_44.lib

IMHO the gd indicates the debug version.

Thanks so far

Simon