MSIE version 6 work offline problem.

All of a sudden IE says working off line.Almost everytime I open IE it is back to working offline. Why does it keep resetting itself? I am connected by cable through a router. Running Win XP home on a Gateway Pentium 2.4 Ghz. 512 ram. 60 Gig HD. Ad-Aware SE, Spybot, Microsoft AntiSpyware,and ZoneAlarm, are all running or used to protect the system.