Here in the UK we are stuffed regarding Super Clean, though I am looking into it!
I have also had the same problems with Halford's primer, though not with solid colours from their own range!
Now I always use their plastic primer or Hycote plastic primer to be safe!
As soon as I source some CSC, I'll let all you UK guys Know!
Oh, welcome to the board too! The more Brits the better!