Some DVD drives don't like certain media, and some media don't like certain drives. It has to do with the depth to which the laser burns on the drive compared to what depth the optical medium is designed to be burnt to. So you' ll find certain mismatches that just won't be happy bedpartners.
That said it is hard to know what the specific problem is in your case. Can you give a little more history?
Did you burn all the DVDs on this laptop drive or on another computer?
Do the '5 of the 25' work in any other DVD drives (on other computers)?
It is quite possible that the offending gang of 5 are corrupted. This depends on the speed they were burnt at (faster = more errors), how compatible the drive and medium are, the state of the drive writing on it, and finally some DVDs are drinks coasters before they ever get inserted in a drive.
If you knew all this already - I'm not trying to talk down to you, by any means. But to find the source of the problem you'll have to go through a process of elimination.
Try to establish that the disks themselves aren't the problem, and then we can look at the drive in your laptop.
I have found Verbatim DVD-R to be reliable and they usually rate top in reviews. Recently Verbatim's DVD+R 16x got the best score, the only bummer being my Toshiba lappy doesn't do DVD+R, being an older beast.
Edited by digikiwi, 25 June 2006 - 04:02 AM.