Hi ,

Not 100% what's causing the problem but the most common cause is malware , your firewall could also be blocking scripts essential for the webpage to run correctly . Also have a look at clearing all cookies and temp files from your pc . Scan with AV and try using some online malware scanners - this will stop any erratic action whilst browsing as the malware application gets blocked . I personally use firethreat ( AV and malware scanner ) and Adware anniversary edition ( both free ) both have online scanners . Another good safety program is spyware blaster - protects browsers from all kinds of threats and runs actively in the background - covers threats for both IE and Firefox .

Hope that helps