Can't use Search Forum

When I try to type in a search request in "Search Forums"

a drop down menu appears of previously typed words,
and I can not get a cursor in the box (where you are supposed to type)

I can use "search this thread"

please help

You should click on the box that opens and type in your search request, then hit enter. I would need to know what browser you're using, etc.

Thanks, I know how to use the search feature, but sometimes (usually after I already have been able to use it successfully, it will suddenly not let me type, but only gives me the option of a pull down menu (list of things I may have used previously, not even all of them on this forum)
I found a work around is to use the advanced search, but still its a little frustrating.
I use foxfire browser, Windows XP pack2 thanks, Jenni