Well it's definately the central locking as I swapped out the fuse this morning hoping nothing would stop working and low and behold the only thing not coming back to life is the central locking! Grrr means I need to find a proper perminent 12v to wire it to rather than solder it to the corner of a fuse.

Scary modification! by Reithryll, on Flickr
I have read a couple of threads whilst trying to find out what physical size the fuse is (as hadn't seen these smaller ones before and was worried they'd be harder to get) and noticed comment of a link to the ecu. I noticed this morning my weird revving issue is back and I'm wondering if changing the fuse has messed with the idle as I've tried tweaking the brake vacuum hose (the seeming culprit last time) and it's made no difference. Any ideas?