I have Office 07. Here's the story: I'm writing an email and I want to copy and paste something I said before. I copy it but when I hit paste, my signature menu comes up. No matter what I do, I can't copy & paste anymore. Why, and of course, how do I fix it?

Does it only happen if you use the keyboard shortcut keys e.g. Ctrl + C and Ctrl + P? or does it also happen if you use the Copy & Paste buttons on the Ribbon?

I don't use the shortcuts.

Hhmm tricky one.. If you were using the shortcut keys I would have said maybe you've accidentally turned on sticky keys or something like that but if you are using the Copy & Paste buttons on the Ribbon then sticky keys wouldn't be affected.
Are you able to take a screen shot (just press the PrtScn button on your keyboard) of what the screen looks like when the signature menu appears and open a blank document in Word and press the Paste button and it should insert a screen shot and upload here?