Quote Originally Posted by Game master pro
I know what your problem is now
It's your CD drive, it is most likely faulty and can only use burnt cd's if they are burned at around 1x. My friend had the same problem, and he ordered ubuntu cds from shipit and they worked fine, so i think maybe replacing the cd drive will work, there not that expensive anymore for just a cd reader. Like only $5 :P
CD-readers are a little more than that for laptops. Old lappy's may not even be findable...

After looking at this, in my case, I figured that the problem only happened on large files being read as a stream off the drive. Small files, no worries.
(Test this by going to a shell, ctl-alt-f2, cd /var/log/mount/slackware/a, and playing... tar -tzvf aaa_base*tgz (works!), tar -tzvf aaa_elflib*tgz (fails after about the fourth or fifth file!))

This makes me think that the electronics can't quite shuffle the data as fast as the computer wants it, nor as fast as the drive can physically read it (it may be a 490x cdrom, but the electronics can only deliver 52x in bursts, not sustained...)

using hdparm to turn off dma (and slow down the read speed on the drive, don't know if that helped or not) seemed to help dramatically.