P38 Auto Selector/Handbrake Problems?

I am having a problem with my P38...When it has been parked for a while I put the selector in D,nothing happens I press the throttle slightly harder & it moves off with a big jerk.If I put the gear selector in reverse first,then put it into D,no problem it moves off as normal.To further confuse the situation this only seems to happen if the handbrake is applied for some time.Any ideas?

Cheers

Steve

It sounds like the handbrake drum or shoes are sticking in the drum,as when say freelander brakes stick on the rear its always best to reverse first normaly with a small clunk and then they come off take off the rear prop and hand brake drum and clean out drum and shoes,might be full of mud and other bits hope this helps.