Any idea about what is causing this? Is there any known workaround for this problem? Thanks.

Thats just how it works when you launch a process in the background on windows, which is what exec does. Windows doesn't have exec, its "semuliated" by perl

Either way interactive <STDIN> is weak sauce

Sure you could go messing with Win32::Console and you might figure stuff out , but I doubt it; a more definitive answer doesn't hold my interest