Mozilla Firefox ( Not Responding )

every 3 min,,when im working with mozilla,,shows me all of page WHITE and not Respoding for few Sec ! why is this error ?
how can i fix it ?!
Answer #1
follow these instructions to create a new firefox profile
http://kb.mozillazine.org/Creating_a_new_Firefox_profile_on_Windows
and see if the issue persists.
also, try visiting
http://mozilla.org/plugincheck
to check that all your plugins are up to date
(note: this creates a new profile, without your bookmarks, addons, history etc, as if you had just done a clean install. If you want to get back to your old profile, use the profile manager to switch)
Answer #2
Hm scan your computer maybe you ahve some viruses.
Answer #3
Try and see if it’s addon.Disable them one by one and test until you find a bad one.