I run ubuntu 9.04 and have installed the w32 codecs as well as flash plug in also java plug in .I use mozilla as browser and can not stream all video types,some video will stream but most do not.for example if i go to zillow .com which is a real estate site and want to see a real estate address it will not show it, it gives you a error message that says "we have encountered a problem"all you get is a circle spinning around you never see the house picture. If you look at a new car video some work but you have to click the forward button all the time because it will not play a 2 minute video clip from start to finish.it will play 15 seconds and stop until you click play then it plays 15 seconds and stops again.

Pls check the following:
> you may be using GENERIC video drivers, therefore the playback might not be smooth., or might have some scrolling issues.
> I have noticed some flashplayer issues specific to Ubuntu (version that I use). Some funtionality might be missing.
> Steaming issues also point s to netconnection/speed. - Check for those issues.