Also, makehole doesnt work. IS this a settings issue?
are the two objects solid volumes? if not, some weird/unpredictable behavior may occur.
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One is a “closed extrusion” and the other is a “open polysurface”… no idea what to do to make either “makehole” or boolean difference work. Please help! 
The open polysurface has it’s normal direction reversed. In other words, it’s inside out.
Use the Dir command with the Flip option to get the little white arrows pointing out.
Then the Booleans will work as expected.
Rhino fixes the normal direction for you when objects are Closed. If they’re open, it up to the user to manage them.
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Thanks John. I managed to resolve the issue by redrawing the object and extruding a new one, but Im going to return to this message next time the problem crops up. Thanks!
This is covered in the FAQ for Booleans too:
http://wiki.mcneel.com/rhino/booleanfaq
thank you.