Follow up from MP
This just in.
Out of the blue this evening I got an e-mail form MP that explains why I;m getting no credit. Here is the e-mail:
"Hi FRequentlander,
Delta created this class of service a few month ago. We checked with them at the time, and they are stating they will not award miles to our members. Our web site shows a W fare but does not show the percentage of miles that Delta awards. The statement "Earning is based on original booking class" is because Delta has been upgrading our members to this class of service, then does not award miles. If you were upgraded, the earning is based on the original booking class. If you purchased this fare, Delta will not award miles.
We are abiding by the terms and conditions that Delta has set with us. We can not change the class of service and if we attempt to post with W class, it is rejected.
Sorry,
Mari P"
So while this is now crystal clear it still seems a but arbitrary on Deltas part. If you buy a W it's like you didn't fly.