Apologies for the small amount of down time.
I'd been advised by my hosting provider to upgrade my installed version of php, plus I'd also seen a comment about their being Adverts being detected by Adblocking software.
So, I tried to upgrade the former and disable the latter (as it wasn't actually configured to work anyways) - and in so doing, phpBB threw it's hands up and caused an issue.
This resulted in an error being displayed....and try as I might, I couldn't see where the issue was coming from and I didn't want to burden our Honorary forum guru unneccessarily...but after a couple of days, I had to ask for help
and sure enough Janos stepped upto the mark (again) and fixed it. 
So, we're back and hopefully all should be well and you can all get your UBT fixes now !!
regards
Tim