Error waiting for DMA

BACKGROUND:
I have a linux based DVR that stopped recording a few weeks ago. When I ssh'ed into it, the log file had repeated warnings about the space on the second partition being empty. However, df showed that the partition was only 53% full. When I arrived onsight, I ran the CD recovery disk that came with the DVR. It starts e2fsck, and begins to scan /dev/hda2, but freezes with this error message:
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e2fsk 1.35 (28-Feb-2004)
/dev/hda2: recovering journal
Checking for bad blocks (read-only test): hda: dma_timer_expiry: dma status ==0x61
hda: error waiting for DMA
hda: dma time out retry: status=0x80 { Busy }

hda: DMA disabled
hdb: DMA disabled
ide0: reset: success
hda: dma_timer_expiry: dma status == 0x21
hda: error waiting for DMA
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I tried to boot a SystemRescue CD with the nodma option, but it wont boot because "there are no ipv6 routers present".

TROUBLESHOOTING:
I eventually just booted the DVR with a Gentoo LiveCD, mounted /dev/hda2, and ran e2fsck from the console. It completed fine, only a couple errors about bad sectors first pass, and the second pass completed with no errors.

However, the DVR still crashed after a couple days, and the manufacturers rescue cd still halted when running its flavor of e2fsck.

I rebooted with the Gentoo LiveCD, and deleted all the data off of the hda2 partition. I re-re-ran e2fsck from the console, and no errors. only 3% used now.

However, when I returned to the manufacturers rescue cd, it still hangs with the same error message.

QUESTION:
I am not familiar with the DMA error message, so I dont know exactly what it is alleging. From my little googling, it seems that it is a mode which can be enabled or disabled (relating to cache?). So:

1) why would DMA crash a manufacturer rescue cd e2fsck, but I can run it no errors from a LiveCD? Is it possible that the Gentoo doesnt load DMA modules by default?

2) how can I fix this? is it symptomatic of a failing HD? Is it possible that a complete low-level reformat (worth the time to try)?

I will try to be fair with points, and spread the love to anybody who answeres any of these questions. I dont know how difficut this is, so I'm not opposed to escalating the points if it turns out to be harder than I thought.

Thanks in advance!

Paul Washburn