Thanks for the response. But that is bizarre. I get a Windows pop-up that says

Perl interpreter has stopped working

A problem caused the program to stop working correctly. Windows will c
+lose the program and notify you if a solution is available.
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What system are you running the code on? If I click "Debug" and open this with Microsoft Visual Studio, I get

Unhandled exception at 0x000000006F4C230B (Piece.xs.dll) in perl.exe: 
+0xC0000005: Access violation reading location 0x0000000000000000.

If there is a handler for this exception, the program may be safely co
+ntinued.
[download]