vz adventra starting and radio problem

[wurzel]

I have an 06 adventra lx6 that does not like starting after I fill up. It fires then stops but starts after cranking for a few seconds then runs fine. Starts ok any other time!
It also has an intermittent power supply problem to the clock / radio. The radio unit checks out ok. Started doing it after it had been parked in hot weather, it would come back on after 20 mins of driving with air con on, then progressed to not working when very cold but coming on when car warms up.
Unsurprisingly local Holden dealers have no idea! Help!
Wurzel