Hi Kieth

>>my question is should i remove it clean as best possible & try re-gen?<<

A yes to that, Like Trevor, I have also has success cleaning dpf's.

I would like to know the reason for re-gen failure though.

22k is not a lot for a six to seven year old car, does it get long enough journeys for re-gen to complete?
Does your scan tool display last re-gen info, ie time or distance?

I have had a couple of D4D's with EGRs sticking that have not logged EGR codes, may be worth a look at that.

Cheers, Tony.