[eluser]philmctim[/eluser]
Just wanted to add my thanks (and a 'gotcha!') to this thread.
I just installed this add-on - took me about 15 mins in total to get the default tests running (and that was the first 15 mins of a Sunday morning - not often that they are productive!)
The gotcha I hit was adding 'simpletest' to the autoload list - it needs to be 'simpletester'. The documentation is correct, I just didn't read it carefully enough.
Thanks again.