Key combination won't run my macro.

I have created a macro and have tried to assigned the key combination to Ctrl+Shift+p via the macro options window. The macro runs just fine if I hit "Run" in the macro window or run it from the VBA editor. I have other macros in my workbook that run when I click a button, but setting a key combination is not working. When I try to set the macro to just Ctrl+p, it does not reassign this to my macro (It still displays the "Print" window.). I have set my macro security to "Enable all macros." Am I missing an option that prevents key combo reassignment?

This site should be useful: http://nhprague.blogspot.com/2012/03...-keyboard.html