Weird behavior -- Crashes firefox when I try to upload, also with webcam it records fine but I can't view the video

I'm running Kaltura CE (1.5) on Mac OSX with XAMPP 1.01

On the management panel i click --> upload --> then choose an m4v to upload... this just causes firefox to lock up my computer and use a bunch of cpu power (89%) ... not sure what the issue is.

Another problem is when I record on my webcam the video shows up fine and I click save... it saves the description and title but when I play back the video its just black.

Any Ideas what the problem is?

Thanks