GU 4.2TI Fuel Shut off Solenoid (Anti Thieft)

Has anyone had an issue with the Fuel Shut Off Solenoid on a GU Y61 4.2TI Anti Thieft Fuel Pump?
My Wagon has been hard to start when warm, Just cranking and not firing. When I leave it to cool or tap the pump and linkages then try again she sometimes will start, but over the last week has gotten worse.
Has gone to United Fuel Inj to get it replaced, Fingers crossed that fixes it or its a $650 lesson...
Anyone had the same probs....
Cheers