My 2 cents for what they're worth...
My old Sony DVD burner created CRC errors, so it very well may be your hardware. I'd start out by going to the manufacturer's site and downloading any firmware upgrades.
If it isn't a hardware issue...it's like Rik said, bad media or buring too fast.
Here's the method that I'd try to see if the CRC errors are caused by the authoring...Try doing an extra copy of each of the DVDs in question and if the CRC errors show up again on the one DVD and not the other its an authoring issue.
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