>I'm not sure whats happening at the 92 megabyte mark, but I would make 
>an observation re the block size you are using.  To me, that seems 
>rather large.  To do a checksum over a 4 megabyte block might 
>possibly be running into a math problem because much of that code is 
>legacy, and probably never expected anybody to use more than 128k, 
>and I personally haven't explored the range above 32k.

Dropping the block size seems to have helped.  Following some
experimentation I got the problem with a 2048k block, but not a 1024k
block.  I've reduced my blocksize now to 512k.  I'll know for sure once
I've backed up and attempted a restore of something big by means of a
test.



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