What Imran seems to think is that my map was possibly causing a boost leak, which in turn was telling the engine to cut power. The map has been tweaked a tad milder, and it's not thrown anything as of yet. Just got home from a long trip and it was perfect. And to be honest, I honestly don't notice any less performance, which is a plus.
Ho did say that this is a first, maybe one of my hoses will need looking at in the future, but its fine at the mo...