Yeah, I could have been clearer about that, I suppose. I used "/bin/rwm" to remount /dev/hdc4 & /dev/hda4 in read/write mode. verified with a "cat /proc/mounts". There are no problems ls'ing any of the files:

mataglap:/drive1/fids/_00022# ls -al 5[1-9]*
-rw-r--r-- 1 root root 3490730 Feb 15 09:22 510
-rw-r--r-- 1 root root 425 Feb 15 09:22 511
-rw-r--r-- 1 root root 3462822 Feb 15 09:22 520
-rw-r--r-- 1 root root 420 Feb 15 09:22 521
-rw-r--r-- 1 root root 3951064 Mar 21 16:40 530
-rw-r--r-- 1 root root 3072 Feb 15 09:22 531
-rw-r--r-- 1 root root 4509214 Mar 20 20:15 540
-rw-r--r-- 1 root root 429 Mar 20 20:15 541
-rw-r--r-- 1 root root 7822961 Mar 20 20:15 550
-rw-r--r-- 1 root root 426 Mar 20 20:15 551
-rw-r--r-- 1 root root 3740671 Mar 20 20:16 560
-rw-r--r-- 1 root root 433 Mar 20 20:16 561
-rw-r--r-- 1 root root 4413476 Mar 20 20:16 570
-rw-r--r-- 1 root root 426 Mar 20 20:16 571
-rw-r--r-- 1 root root 6923714 Feb 15 09:23 580
-rw-r--r-- 1 root root 435 Feb 15 09:23 581
-rw-r--r-- 1 root root 5663889 Feb 15 09:24 590
-rw-r--r-- 1 root root 428 Feb 15 09:24 591
mataglap:/drive1/fids/_00022#

and I can cat 521 & 541 successfully.

--Nathan