I've been having problems for several weeks with using cut and paste in Firefox and have been thinking that I must have picked up some virus or something, even though nothing was ever found when my system was scanned. I just figured out what the problem is: the otherwise very useful Auto Copy extension. Auto Copy will automatically stick text in the copy/paste buffer as soon as it is selected. This is fine, but if you are doing a lot of editing in text boxes and use selection to grab and delete text, it will give you fits, because what you thought you copied will be replaced by what you just deleted. Therefore I suggest you do the following:
- Right click on the "Auto Copy Enabled" area on the status line and select "Options..."
- Uncheck the box called "Deselect after copy"
- Uncheck the box called "Enable in Text Boxes"
- Press the "OK" button.
Your editing habits are probably different from mine, but the above actions may help keep you productive and sane.