Why do I get a faded quicktime sign with a question mark in the middle of it, when I try to look at certain quicktime streaming files. Sometimes it works, sometimes I get that sign.

It doesn't appear to be to do with the flash player problem, which people mentioned. I checked the plugin preferences and the flash plugin box is not ticked. The other suggestions I found all seem to do with Apple Mac's. I just have a normal desktop computer.

Does anyone know of any solutions????