Vista cannot see DVD media but other software can

If I try and burn a data DVD from a drive folder window using the "burn"
button the attempt fails - because it says: no writable media. Vey well,
Windows DVD Maker has no problem burning a picture file to the same disk, as
can the stand-alone program DeepBurn which burns data to a dvd -r with no
problems. Vista has no problems reading CDs and DVD data disks, so what is
the problem with Vista not seeing the same media to burn??????
Thanks,
HalD