Mark has been one of the most unlucky players (and in his case luck rather than his action has been largely responsible) with injuries.

This season he suffered a stress fracture of the lower back (ok could be he needs to remodel his action but read on.) putting him out for the remainder of the season when he had reached 47 wickets.
Last season he suffered a side injury which put him out for the last few matches of the season.

A couple of years before that just as he was breaking in to the 1st XI he was involved in a serious car accident in (multiple fractures and a collapsed lung) it took quite some time for him to recover from that and any problems with his action putting stress on his back a side may well be traceable to the effects of the injuries.

That said I would like to see him spend some time with Troy Coolley and the England techies to analyse his action and hopefully do something about his tendancy to pick up injuries.

Mark may not have express pace but he has shown over the last two years that he certainly has something
Could be an English version of Glenn McGrath who isn't the fastest bowler around either.

I have seen Mark produce some absolutely devastating spells along the lines of 5 overs 4 maidens 3 wickets 1 run this year. I will look forward to the start of next season with Mark, Liam Plunkett (England ODI squad), Steve Harmison, and Mick Lewis (Australian central contract player) bowling as Durhams seam attack until the test series starts at least.
Any of the 1st Division fancy facing Durham on an early season greentop with that lot in harness?