DVD-RW media

[Joyce Ranieri]

It was suggested to me a while back to do a "first run" with my DVD 
projects on DVD-RW media. I've tried to do this, but once I've written 
a project once, the computer doesn't seem to recognize the DVD as 
writeable. Is there something special I need to do to make this work? 
Will all Macs do DVD-RW? My computer is a 17"flat panel iMac, 1GHz, w/ 
superdrive running Mac OS 10.3.2 and iDVD 3. (I just installed iDVD 4 
but haven't had a chance to use it yet.)

Joyce