I remembered only having that problem with IE
Its probably because I am using IE 6 (came default on the machine) instead of IE 8 which I just downloaded recently too. Damn it. This whole thing just pisses me off so much. 
It does happen on IE 6.
Now we know, but thanks, had I not solved you came the closer to providing real help. 
I know because I'm typing from a computer with IE 6 right now. The highlighting issue isn't a problem if you're highlingting the contents of a text box, however.
The school computers at my high school must have had IE 6 is well. If its a computer you or someone you know owns, I would suggest downloading and upgrade for to IE 8. I would also suggest finding one optimized for your OS and ISP.
In most cases, I do work with IE 6 for school purposes.
Otherwise, I have IE 7, but I won't be upgrading to IE 8.
That reminds me, Microsoft is now working on IE 9. They're finally moving away from Windows XP, too (and I reckon it won't work on Windows 2003 either; it requires Windows Vista or later).
