Preview Playback Problem

Hi folks,
I just built this new internet computer and I've got the latest Flash player installed but just when it looks like a preview here is going to play, the preview pane just turns white. Any ideas?

ZR media

It's been doing this for me for about a month. My preview stays black with all the play - pause - controls looking normal. Just no video play. Using Firefox, newest updates also. If you figure it out let me know.

I've been building a website for my clips, and placing the video code on the pages; in IE it's mostly just black, some show the pictures but don't play. Seems to be working better in Firefox. I've been doing pages for each place I've done clips, so I am hoping I am not putting too many on each page, and slowing down the loading. I'm also looking for possible WP plugins to speed it up?