Data I copy from Excel 2004 won't paste into Prism Mac.
If you use OSX 10.2 and the original release of Office 2004, you wont' be able to paste data from Excel into Prism 4 Mac.
The best fix is to update Office 2004 on microsoft.com
Upgrading OSX will probably also solve the problem.
The alternative work around is to paste into textedit, and then copy (again) and paste into Prism.