onmouseover causing processor to spike

I have created a client side tree-control using DIV tags.
Within a DIV tag, I have a table structure with 3 columns and 2 rows.

The tree-control forms a Parent - Child relationship where child DIV tags are appended within TD tag of their Parent DIV tag.

I have onmouseover event in a TD tag (within the DIV tag). The onmouseover event calls a function. When I bring the mouse over the DIV tag the processor spikes. I tried putting window.event.cancelBubble=true; in the function that is called by onmouseover event but it did not work.

Any ideas what could be causing the Processor to spike? Any help is appreciated.

What version of IE and Windows are you using?

Do you ever get the dialog box that says a script is causing the program to run slowly?

Are any JavaScript errors occuring/generated?

Does the processor also spike when using Netscape?

Do you have any extra IEXPLORER.EXE processes running? (browser windows that you closed but still have a process running in the Windows Task Manager)

Could you provide the code for the function being called?

Wait! you better provide the whole code because you said that when you put the mouse on the DIV tag not in TD, of course am I right?:D