If you are talkin about a 90 min disk, you need a burner that will burn more than 80 minutes. Most burners dont so they use the disk as an 80 min disk!
The disc is always recognized as 80. You must overburn until 90 : the program will tell you there is not enough space, answer that you don't care and want to proceed burning.
To avoid wasting a disk, if you use nero, make sure before overburning that you click file - preferences - expert features and tick allow overburning and set the limit at 90mins or higher.
