I am finding that on some web sites quicktime sometimes plays improperly in Firefox in a recent build. I get a blank white screen but the audio still plays. I have spoken to others who are experiencing the same issue. The issue will sometimes resolve itself if the window is resized, the scroll bar is moved or the page is refreshed. The later only works occasionally. It is not occurring on the machine that I'm writing this from. It is happening on both PPC Macs as well as Intel Macs.