CS3 Flash Video XML, .f4v

I hope someone can help? I had recently converted 8mm film to a .mov then to .f4v. I had created a multi resource video player in Flash CS4 and using XML to tie in the video from external… .f4v video is getting pulled in from a “video’s” folder. When I play it locally on my laptop it plays all the way through to the end- “5 minutes” But then I uploaded the contents to my hosting web server and played it. It played but it would freeze then start, freeze then start. Then it froze completely. then I had to “refresh” Web browser. Does anyone know what might be causing this and how can I fix it. please this is for my dads 65th birthday surprise if someone can contact me I would appreciate it very much. I would gladly send over any files need to examine… I’m thinking its the way I am encoding the .mov (bit rate to high) if so, what settings do I use? thank you in advance I look forward to hearing from you.