I have access to a PDW-F75 and a PDW-U1. I load a new 50GB disc into the F75 and it formats it, then I take that disc and load it into my U1. Then in Avid, I select my sequence and export to XDCam Device. After it's completed, I open the XDCam Transfer Utility to double-check everything is written to the disc correctly. Then I take the disc to the F75 to see if I can play it back, but I'm getting "No Support!" on the F75's display screen.
I realize that this is probably because the disc was formatted as 1080i/59.94 and this particular sequence is SD and exported at MPEG50. However, I thought it was possible to mix and match SD/HD on an XD disc provided the frame rates were comparable (which in this case they should be).