Weird Audio Issues

I currently work at a company who supports students who connect to Live Lessons using the Adobe Connect software.

Recently quite a few calls have been received where a user has a Windows XP SP3 machine using either IE 8 or Firefox and the only way they can hear clear audio in a Live Lesson room is to either minimize the window or cover the meeting window with another window.  This only occurs in IE 8 and Firefox.  The workaround we are using right now is to download Chrome which works perfectly fine.

We have only seen this on Windows XP SP3 machines.  Thanks in advance for any suggestions.