Thanks for the help. I just wanted to make sure this was my problem.
I solved the problem:
I used Hash Calc to generate the md5 checksum from the my downloaded .iso file and manually checked it against the md5 sum in the release notes and they were the same.
I then deleted the old .md5 file and rebuilt a new one from scratch and ran MD5Summer (my normal MD5 check program) and it checked ok this time.
I must have had a bad character in the .iso file name even after I rechecked it. The funny part is that I cut and paste most all data to make the .md5 file. I must have built an .md5 file over ten times for other .iso's and had no persistant problems like this one. Most often the .iso's are accompanied with a pre built .md5 file for download.
Dave