[Paranoia] non-reproducible rips? (not a FAQ, I think)

[Eric Sandeen]

I'm running "cdparanoia-alpha9.8-15" from the RH9 distribution (yeah 
yeah, time to upgrade!) and after talking with my audiophile friend 
about rip quality, decided to do some investigation.

I have 2 drives in the box:

[root at porter root]# cat /proc/ide/hda/model
PLEXTOR DVDR PX-504A
[root at porter root]# cat /proc/ide/hdb/model
Pioneer CD-ROM ATAPI Model DR-A02S 0108

as expected, the plextor does well, and md5sums of 3 consecutive rips 
all match.

The Pioneer drive is another matter... while ripping with a simple 
command such as:

cdparanoia -r -d /dev/scd1 7 foo

I get output like:

(== PROGRESS == [+                    ++++++++| 125439 00 ] == :^D * ==)

Now I thought that a "+" error was recoverable... but 3 consecutive rips 
of this track give me 3 different md5sums.  Fine, I think, this is 
covered in the faq, it's just the starting point.  But after hexdumping 
& diffing, I see differences such as:

--- cheapo3.raw.hex     2006-01-01 16:42:46.000000000 -0600
+++ cheapo2.raw.hex     2006-01-01 16:40:37.000000000 -0600
@@ -3523113,8 +3523113,8 @@
  35c4210 efd4 f08c ec77 edec eefc f07f ef71 f147
  35c4220 ed33 efdf eec4 f13a ef3d f15a ebc6 edf6
  35c4230 ecf7 eef9 f14c f2c8 ed41 ef7d e763 ea47
-35c4240 ebf8 edf2 f268 ef4c efd8 f0a7 e7a1 e9af
-35c4250 e574 e7f3 e86d ec51 eb67 ed1b e6da e917
+35c4240 ebf8 edf2 f268 f315 efd8 f0a7 e7a1 e9af
+35c4250 e574 e7f3 ea59 ec51 eb67 ed1b e6da e917
  35c4260 e14a e478 de71 e26a e405 e726 eb0c ed1d
  35c4270 e739 ea25 deed e334 dd8d e237 df4d e43d
  35c4280 e04d e52c de8b e344 ddb6 e20e e262 e608

and more after that...

now this looks like a bona-fide non-recovered data read error.

Is this to be expected?

thanks,

-Eric