Hi Mike.

You may be having a problem with some extension or plugin that is hindering your Firefox's normal behavior. Have you tried disabling all add-ons (just to check), to see if Firefox goes back to normal?

I have already tried that unfortunately and it didn't help. I also tried repair permissions.

Have you tried reinstalling Firefox? (not information will be lost in the process).

I've tried that too

Use the Profile Manager to create a new profile and see if the problem persists (don't forget to go back to your own profile, this is just for diagnostic purposes)

See Firefox repeatedly opens empty tabs or windows after you click on a link

Thanks cor-el. Seems to be working now.

You're welcome