Can anyone shed light on this issue?

I've just upgraded to IE6... now when i try to run a client side XML 
application, after a while I start getting "Attempt to modify a read-only 
node" whenever I try to modify the value of a node.  I have to restart the 
machine, and then it works for a while and it happens again.

I used to get this with IE5, but installing the SP sorted it out... there 
is no higher SP for IE6 that I can install.  any ideas anyone?  someone 
must have experienced this!

cheers