Something is up with my Superdrive...can anyone help

Question

I am struggling a bit with a fault on my Superdrive and questioning whether or not to return it under warranty. I haven't seen a similar issue on the forum and I hope someone out there might be able to help. Here's what's going on:
I am trying to copy some photos from a DVD to my desktop. The DVD goes into the drive fine, it then shifts what appears to be a random number of images to my desktop fine with no problem. However after a first burst of happiness it goes AWOL on me. The data rate drops down to 1-2Mb per minute for a period of time with the drive speeding up and slowing down continuously before giving up entirely with the error below:
"The Finder can’t complete the operation because some data in “PICT00441.MRW” can’t be read or written. (Error code -36)"
After this point the iMac needs to be powered down before you can try again.
It's the same for other DVDs with image files but audio and data CDs/DVDs all seem to run fine and I've had no other problems with the drive.
So here's what I've got (all the last software updates applied).
iMac 24" 2.93 GHz
Snow Leopard
The drive is:
PIONEER DVD-RW DVRTS08:
Firmware Revision: Q81D
Interconnect: ATAPI
Burn Support: Yes (Apple Shipping Drive)
Cache: 2000 KB
Reads DVD: Yes
CD-Write: -R, -RW
DVD-Write: -R, -R DL, -RW, +R, +R DL, +RW
Write Strategies: CD-TAO, CD-SAO, CD-Raw, DVD-DAO
Media:
Type: DVD+R
ID: CMC MAG M01
Blank: No
Erasable: No
Overwritable: No
Appendable: Yes
Write Speeds: 2.4x, 4x, 6x, 8x
Any suggestions as to what might be causing this or anything I can try?
Thanks.

Answer 1

+it then shifts what appears to be a random number of images to my desktop fine with no problem.+
If you're copying all of the files on the dvd, they're not being copied in numerical order, just being copied simultaneously, with the randomness of the result due to which copies fastest.
The file that doesn't copy successfully, can't you just deal with it individually until you get it to copy? I don't have an .MRW file, but if you try the most simple method of dealing with it, which would be changing "MRW" to "jpg" - won't the iMac try to reformat the file to accommodate what you want by using whatever software you have installed, or by recommending what you need?
Not an area of expertise for me, so that's all I can add, other than to advise I transferred some old files that couldn't be dealt with until I installed a minimum of Photoshop 3 - so I went with the least expense, Elements 6, and it did what I needed - modernized the files so that I could save them as jpg and add them to the others stored in iPhoto.