Hi Darren,
I had this situation on one of my first starts with the 44. Got a cracking video of it

luckily it was on the bench, and all we did was initiate shutdown/cooling, and then went for another start.
We've now got accustomed to turning the valve off after shutdown, however I don't want to risk forgetting at the field, so ordered a solenoid valve, which arrived today. Better safe than sorry.
Another new situation we found last night, was that we slowly shut the gas off, and after letting it sit at idle for a few seconds, went up towards full power. We got a lot of flaming and the temp rocketed. I quickly brought throttle back, and initiated shutdown.
Went for another start, and all was fine. We presume it was air in the line?
One other question from newbie me: If the fuel tap is left on, to get the fuel out, is it just a case of initiating the start proceedure, just without the gas on?
Cheers matey
Dave