Where are you trying to paste?

Also, how are you trying to copy? (Ctrl-C, right click, some other way?)

I'm trying to copy by highlighting text and and right clicking with my mouse. As far as text, for example, if I try to copy the text in your message, I can't.

Try shutting javascript off.

Also ,I play evony and they use flash to display messages and copy don't work with that. I use a image capture for that.

does it matter where i'm trying to paste?

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of your add-ons is causing your problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).

• Don't make any changes on the Safe mode start window.

See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems and Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems

If it does work in Safe-mode then disable all your extensions and then try to find which is causing it by enabling one at a time until the problem reappears.

• Use "Disable all add-ons" on the Safe mode start window to disable all extensions.
• Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")

See also http://kb.mozillazine.org/Clipboard_not_working

Is this a recent problem...after the last update on Oct. 27, 2010? Were you able to copy and paste before the 27th? My optical marble mouse has had a breakdown from the update. No longer can I do a smooth scroll in Mozilla. However, I can in I.E. and Outlook Express. I posted on the 28th.