Neil it could have been the acid rinse, I was told by Julie Roberts of Chemspec (this women is impressively knowledgeable) that acid rinses cause resioling, I'm not saying not to use them as I use them more diluted than the instructions say and therefore i really don't think it will in any noticeable way.
I recently tried power burst side by side with another pre spray by texatherm, it was not not a patch on power burst, I'd be interested in hearing results of side by side with shockwave and smp.
Simon why is PB in reserve? In case Shockwave and SPM cant cut it?