A rare visit to Birmingham

I went there to see if Apple could advise on what I consider a rather slow start-up time for my MacBook Pro (around 50 seconds). It passed all the tests (more extensive than the tests and various other things I'd already tried myself). The suggestion was that extensions to the kernel are being loaded, and these are slowing things down. Possible solution - try wiping the disc (after backing everything up!!!) and reinstall OSX and the Time Machine backup, but with settings disabled from the Time Machine restore. News on how successful this was to follow.