dvd-r discs, are they all the same

[kimanddave]

i have been using nero to burn dvds with no problem until now.i have just bought some maxell discs and when i try to burn anything onto the dvd it says"cannot copy illegal disc".im using dvd-r and have done in the past with no problem,what am i doing wrong,thanks

[maviscoull]

is it maybe the maxell disc !! i can play aTDK DVD-R on my player but when i put a MAXELL DVD-R in its says unknown disc ! any thoughts on this welcome !!