[CentOS] Isolinux disk error 20; AX=4280, drive EF

Sat Aug 2 18:37:48 UTC 2008
Ed Westphal <enwestph at rochester.rr.com>

I thought I'd be clever and buy a DVD for 5.2 from LinuxOnline.biz.
Well, just got around to trying it with the above results. Does the
error mean I have a 'bad' DVD disk image? Please advise. Thanks.