Saving Movie in Movie Maker

This could be very simple or hard not sure which. I am making a movie though
so its important. I have been making about a dozen smaller movies to
consilidate into one large Movie Maker file when I am completed with them
all. Along the way I have been watching parts by saving just that part and
watching them on my TV (to ensure the titles and what not are good). Anyhow
today I went to save a part and the save movie box came up as usual (its
sonic DVD) but WINDOW MEDIA PLAYER STARTED, I thought that was weird, but the
movie seemed to save fine, but then I noticed that the save speed box was at
4X, which is always auto, THEN the whole thing completed but then said WINDOW
MOVIE MAKER COULDNT FINISH THE MOVIE BECAUSE OF AN ERRor, then when I CLICKED
retry it said that 4.X recording (which curiously was my only option)--
ALTHOUGH my discs are up to 16X, "this speed not supported" WTF???
Anyhow, I need the project soon and there doesnt appear to be a problem with
WMM, so Im curious its got to be one of three things (EITHER BY DVD WRITER)
the discs (I just opened a new 100 case spindle today) or SONIC. I can take
back the discs and if the writere then so be it. But if its sonic, how do I
make a new player by burner? I fiddled around with Windows Media Player and
couldnt get it to burn the WMV file I had so. ANd even so I went into WMM and
couldnt even figure out how the hell it picked SONIC to record my DVD's. So
if I figure out its sonic how do I change the settings in WMM so that it
"looks" somewhere else to record a DVD?
thanks
RON