Hi,

I opened your PPU workbook and find your code behind a worksheet instead of in a module. This raises a red flag for me in terms of SCOPE (not the mouthwash). My general rule is that code behind a worksheet only works on that worksheet. If you want to pull stuff from another sheet or workbook you should have your code in a Module that can see other sheets or workbooks.
Read http://www.ozgrid.com/VBA/variable-scope-lifetime.htm
for more info on the topic.

Scope of VBA is like creating a variable using the Dim statement in a subroutine and trying to use it in another. The variable is destroyed as soon as the sub ends, unless you declare it as global.....

If I'm way off base, keep asking and we can read the code but having your VBA behind a worksheet instead of behind a module is my first guess of the problem.