Folks, As much as I hate to, I feel I need to post my long story and ask help. Shortly after the release announcement, I kicked off rtorrent and downloaded the CD and DVD images. Since my cable provider does my "throttling", I disabled throttling and shared for several days, "returning" several GBs at no objectionable loss I could discern. While that was going on, I used cdrecord (don't jump to conclusions here, read on) via CLI to burn the CDs. This on a fully-up-to-date CentOS... well here uname -a Linux centos01.homegroannetworking 2.6.9-42.0.10.EL #1 Tue Feb 27 09:24:42 EST 2007 i686 athlon i386 GNU/Linux $ lsb_release -a LSB Version: :core-3.0-ia32:core-3.0-noarch:graphics-3.0- ia32:graphics-3.0-noarch Distributor ID: CentOS Description: CentOS release 4.4 (Final) Release: 4.4 Codename: Final CD writer is a generic 52x24x52x that I have used to burn many CDs before w/o problems. On this unit and the other I'll mention, the writer is master on IDE channel 2. Neither has an HD on that channel currently. The other unit has SATA drives and the writer is again on IDE 2 by itself. Disc 1 passes media check and 2 - 6 fail consistently. Checks OK: ...CentOS-5.0-Old]$ md5sum -c md5sum.txt CentOS-5.0-i386-bin-1of6.iso: OK CentOS-5.0-i386-bin-2of6.iso: OK CentOS-5.0-i386-bin-3of6.iso: OK CentOS-5.0-i386-bin-4of6.iso: OK CentOS-5.0-i386-bin-5of6.iso: OK CentOS-5.0-i386-bin-6of6.iso: OK CentOS-5.0-i386-bin-DVD.iso: OK IIRC, I also used the sha1 check (can't recall the command ATM) and it also passed. "NP" says I! I'll copy 'em over to my LFS machine and burn on the Lite- on DVD/CD* burner. Same results. Hmph. OK. Rtorrent unreliable (don't giggle - there's a difference in the images as evidenced by "cmp" below)? Download all but the DVD directly from the UofGA mirror. Save them in ...CentOS-New. Do similar things. ...CentOS-5.0-New]$ md5sum -c md5sum.txt CentOS-5.0-i386-bin-1of6.iso: OK CentOS-5.0-i386-bin-2of6.iso: OK CentOS-5.0-i386-bin-3of6.iso: OK CentOS-5.0-i386-bin-4of6.iso: OK CentOS-5.0-i386-bin-5of6.iso: OK CentOS-5.0-i386-bin-6of6.iso: OK md5sum: CentOS-5.0-i386-bin-DVD.iso: No such file or directory CentOS-5.0-i386-bin-DVD.iso: FAILED open or read md5sum: WARNING: 1 of 7 listed files could not be read Burned the CDs again. Media checks same as before - 1st passes and all others fail. Did again on the LFS machine, same results. All media as RW, some <=12x, some <=4x speeds. Was rewriting over media previously used for CentOS 4.0 install (keeping 4.3 CDs available) and other miscellaneous previously used RW CDs. Well... maybe they are bad now? All the ones I tried?! Unlikely. But be the type to avoid assumptions, burned disc 2 again on new media. It still fails. Jorge, in his long-running condemnation of Linux kernel SCSI implementations, again mentions his usual in the docs he provides and specifically states that kernel >=2.5 has problems (at least the rants about the wort-ever SCSI implementations have abated). So I figure I'll use something that does not involve CLI. BTW, by now I've learned that there are differences between the rtorrent created and downloaded-from-mirror images. So I go to my trusty CentOS desktop, get nautilus going, right the disc 2 image and write to CD. No improvement. Last data point. Right after I downloaded from the UofGA mirror, I did a cmp. All the rtorrent vs direct download images showed a byte difference at offset 32768 of "line 1". My rtorrent was still running (IIRC) serving others. OMG! Am I delivering corrupted images to many other users! I immediately shut down rtorrent. When I do the cmp *now*, now differences are noted. I checked cable seating on the "target" machine. OK. I tried reading the CDs on the same unit(s) that created them. I'm now suspecting "wetware" problems. ATM, I probably can't see the forest for the trees. Any thoughts, wisecracks, suggestions are welcome. TIA -- Bill