Update.
I've discovered that my pedals are much happier when they are permanently daisy-chained together on a board as opposed to being broken down after a gig and put in separate boxes. Apparently they feel more like part of a team and so believe they work and sound much better together. Personally I don?t understand what they?re on about as it all sounds the same to me.
Anyway, I suffered a few problems with my old Vox wha-wha who, on the grounds of his senior position on the 'board' (ohh dear), 'flatly' refused to have his battery removed (please stop!) and permanently replaced with a 9v supply. Subsequently I had to let him go. His replacement is a "Clyde" unit who seems to be whaing nicely.
Periodically a row flares up between the 9v and 240v camps that usually starts with the 240's humming wildly out of tune. However, this is usually rectified with a wiggle of the wires or by delivering a swift kick to the biggest box.