Do you have a modified air filter or air intake system? There was someone last year that posted a similar regeneration issue to yours. He indicated that his truck was stock other than the air filter system. I believe that GM voided his warranty and he was very upset. If your truck is modified I would try returning it to stock and see it it fixes the problem.
Good luck
John
*2006 Chevy, 3500, 4X4, DRW, (LBZ) D/A, CC, LT, 252K Miles, 19.5" Wheels, Mag Hytec Transmission Pan and Differential Cover, SS Grill Guard, Racor 2 micron aux fuel filter, 100 Gallon Aux Fuel Tank, using Edge Evolution, Predator Diablosport, Kennedy ECM tune, Fitch Fuel Catalyst.
*2006 Four Winds, Dutchman, 36', RV, D/A, 5500 Kodiak.
*1993 Harley Davidson, Turbo charged, Springer Softail.
*2007 Pontiac Solstice.
*2005 Jeep, Liberty, CRD (diesel).
*Full-timing in USA, see America first.
BUY AMERICAN or CANADIAN, NOTHING from CHINA .