This isn't actually a "lock-up". If you select the option to continue (allow the script to continue running), everything will work fine.
This is due to a Microsoft Internet Explorer script "feature". It is designed to prevent a web page from locking IE up by entering into an infinite loop.
When you visit a web page that contains Javascript (and a vast majority now do), that script code doesn't typically run "all the time". Meaning, it will run just after the page completes loading, when you exit the page, or when you click on something on the page, or even when you just hover the mouse cursor over an item on the page. Something triggers the code to be run, Internet Explorer runs the code, and when it is done control is handed by to IE. While the code runs, your browser is typically unresponsive, but that's OK because usually the code runs for just an instant.
If the code were to go into an infinite loop (and thus never stop running), then IE would "lock up"; it would remain in that unresponsive state. To prevent this, Microsoft added a "feature" that simply limits how many instructions that code is allowed to perform at any given time. If it exceeds this (arbitrary) threshold, IE intervenes, putting the code on hold, and asking you if you want to allow the code to continue. This is the dialog message you see in the Tournament Director. This "feature"
should be disabled for HTML applications (which the TD is), but for whatever reason this appears to have been overlooked.
On the TD Stats page, a lot of code is being executed in order to compute stats. (This is, of course, dependent on how many tournaments you have.) Obviously, the threshold is being reached. All you need to do is allow the code to continue.
Luckily, Microsoft provided a way to get rid of this entirely. Well, sort of. The default threshold is 5,000,000 (meaning 5 millions instructions are allowed to execute before IE intervenes). You can increase this threshold if you want and effectively do away with the warning. Follow the instructions in this Microsoft Knowledge Base article if you want to do this:
http://support.microsoft.com/default.aspx?scid=kb;en-us;175500