Do a malware check with some malware scanning programs on the Windows computer.
You need to scan with all programs because each program detects different malware.
Make sure that you update each program to get the latest version of their databases before doing a scan.

• http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
• http://www.superantispyware.com/ - SuperAntispyware
• http://www.microsoft.com/security/scanner/en-us/default.aspx - Microsoft Safety Scanner
• http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page
• http://www.safer-networking.org/en/index.html - Spybot Search & Destroy

You can also do a check for a rootkit infection with TDSSKiller.

• http://support.kaspersky.com/viruses/solutions?qid=208280684

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

Tried all of these, most of which I use already. these are the only sites that I use with this issue. They are both sites from the same company. This was not a problem until a couple of firefox upgrades ago. For what it's worth my lap top same version of Firefox windows 7 64 bit. has the same problem.

Thank You

I added them to the whitelist in Ghostery and now working.

Had found this problem it was only one data miner ( Geoplugin). Thanks for your efforts.