When I have an instance of firefox open and then open another instance it takes 3 minutes to open up. This only happens on occasions and has been happening for almost 2 weeks now. What is causing this and how can I fix it?
It sounds like it could be an add-on trying to check for an update when you open the new instance, for this I'd suggest going over all the add-ons (if any) you have installed in firefox and see which one's are set to check for updates at startup, then change them so they don't check for updates at startup maybe.... OR perhaps it's Malware.. unfortunately these days Malware is getting rather good at avoiding detection.. for this I'd suggest running some scans with whatever Internet Security/Anti-Virus app you have.. if you don't have any than I'd suggest using something like NOD32 or one of the free alternatives like AVG or Kaspersky... etc... Hopefully this is helpful in some way... It really sounds like an add-on problem though...
First thing I am trying is disabling all my add-ons and see how things go. As for malware or being infected, I have kaspersky internet security 2009 and I scan fully every sunday. I also have malwarebytes anti-malware and do full scan every tuesday. Finally, I have adaware free edition and do a full scan every thursday.
I also use spyware blaster. I doubt there are any malware issues.
I am not saying this is your problem, but when I was using KlamAV antivirus realtime scanning in Linux. It made Opera take over 30 seconds to launch. Firefox was not affected much. Not using KlamAV realtime scanning let Opera launch in a couple of seconds. I also discovered that if I restricted the realtime scanning to certain directories, Opera would launch quickly.
The above would seem to indicate that perhaps your antivirus software or firewall could be causing your problem. You could try disabling them for a test.
EDIT: It appears that you may be having more than one antivirus and antispyware application running at the same time. This is not recommended. You can have more than one on your computer as long as they are not running at the same time.