If you were to log in, you'd be able to get more information on your fellow community member.
I've had similar experiences, but only when working on the pc. To me it seems as if PC video software just isn't too good. On the mac, Quicktime has been a standard for a long time, and the editing software on this side of the platform is a lot more mature and easier to use than on the pc.
For extremely good video rendering quality (such as scaling video down) I recommend Adobe's After Effects (as opposed to Premiere).
Also, if you're frustrated at Realvideo and their software, take a look at the newly released Quicktime 3.0 (http://www.apple.com/quicktime). QT3 now has very good video codecs aimed at the net, and looking at some test I've done and the demo files on the Apple site, it looks like it's pretty safe to say goodbye to Realvideo on most projects...
Jussi Haro Grey Interactive Helsinki