When I render using the automatic preset I get 25.000Kbs (max), 10.000Kbs (med) and 5.000 (low), but when I use the fixed rate window I only get 6.000 Kbs, no mather if I write 10.000 or 25.000.
I have the same problem and also when I capture dv files via QT and import them in Final Cut the size changes to 1049×576 and square pixel. The info panel of QT says that the clip is 1024×576. Now I have always to capture with Final Cut to get right size in the movies.