DeBug is this why?

win2K, pentium4 system, 50 user Lan.
user had a ‘run time error – do you wish to debug’ come up whilst on the internet.

the user said Yes but debugging never took place, (could not set the value property) now he cannot get a cursor into drop down boxes such as where you type a ‘Search request’ this is not restricted to any particular web page.

can anybody help? hope i am in the best section for this!
thanks, JohnM