Nero & md5

Here is my problem.

I was using Nero 6.6.15 to burn an ISO DVD file. The ISO contains lots of compressed files. Nero verification said “successfully”, but the files were having CRC-check failure when uncompressed.

I know that MD5 creation will be more reliable, but how do I create MD5 for the contents of an ISO image ? I know how to do it for folders or list of files in my harddrive (before burning), but for an ISO image ???

Is there any MD5 plugin for Nero that automatically create & include MD5 checksum when burning ?

How does MD5 checksum differ from Nero burning verification ? I believe they are used for the same purpose, but certainly Nero verification is very unrealiable.