Bizzarre IE problem


Licensed Computer Geek
Here's a weird one: lately, when I've been using Internet Explorer, I've noticed some strange behavior. Everytime I switch to another running app, and then switch back to IE, it hangs and does a beach ball cursor for almost 10 seconds. Does anyone have any ideas about this? By the way, I'm using 5.1.1, and I've already tried emptying the cache and clearing the history list.