How do you read the CPU? I pulled it up and see some spikes in the graph but have no idea how to interpret it.
The chart just shows overall usage, you need to click the tab called "processes" and sort them by the cpu% column so that processes using the most cpu are on top.
When TD locks up, you might see a process jump to the top using lots of cpu. Or you might not. I'm really just taking a stab in the dark here.
You could also try disabling all your IE add-ons and see if the problem goes away.
Really, really hard to solve flaky problems like this.