[olug] Checking DVD ISO MD5s after burning?

[K.J. Kirwan]

I like to run an MD5sum after burning a CD-R, to 
verify a good burn, especially for distro install ISOs.  
Recently I upgraded to a DVD burner. (+/- R/RW).  

I can still burn & read back good MD5s on CD-R ISOs, 
but I haven't been able to read back a good MD5sum after 
burning a known-good DVD ISO to DVD+R.  I am not sure if 
the DVD file structure allows this.  Google hasn't helped. 

The DVD burn appears to succeed, in that I can see a 
bunch of files and folders that look OK to the eye.  

Is anyone burning DVD ISOs and reading back good MD5s?  
How did you do it?  K3B?  command line?  Something else?  

Or has anyone gotten K3B's "verify files after burning" 
feature to "pass" successfully?  How did you do it?  

If it helps, I'm using Mandrake 10.1 Official (w/ updates).  
First DVD burner tried was a LiteOn SOHW-1633S.  Upgraded 
firmware from BS0A to BS0S with no observed difference.  
Second DVD burner tried is a Plextor PX-716A.  
Media tried so far and pass/fail results are: 
CD-R, Imation (Pass).  DVD+R, TDK, 8x (????).  
DVD+RW, Fujifilm, 4x (????).  
I have not yet tried any DVD-R or DVD-RW media.  

I'm also interested in any DVD+RW experiences.  Can't I 
delete/add files/folders one by one, as on Win32 Adaptec 
"Direct CD"?  I'm not crazy about K3B's "erase completely 
when first inserted" option.  Same with "force reformat", 
said to only be doable maybe 10 or 20 times (hard on disc?).  
Any advice?  Did I miss the "obviously intuitive" method?  

I want to use the above either for burning a distro install 
DVD ISO to DVD+R media, or getting a data backup onto DVD+R or 
DVD+RW, and then verifying that these were done sucessfully.  

Any popular mistakes or common misunderstandings here?  
Thanks for any help or suggestions.  

Kim