Pop up box keeps recurring every 45 minutes(approx),shutting down mobile broadband connection to "3" network. Found way around by switch off and reboot,but that severely disrupts online working. Suspect overactivity of processor leading to moderate overheating. Using XP Pro SP2 on Thinkpad T40 with PC Tools Int/Sec 2009 and PC Tools Registry Mechanic. Scans with both tools show as "Virus-Free"/"NoProblems". Websites with lots of content seem to trigger it, E-bay being a constant example.