DBI::trace? When he's not even using DBI, but Win32::ODBC? No kidding...

Perhaps the OP could indeed try using DBI+DBD::ODBC instead. I see no %SIG manipulation in the perl source of Win32::ODBC — $SIG{INT} is the way to capture the signal coming from ctrl-C. So I can only guess that it hangs in the XS part (the DLL) of this module...