Speed Demon

Been working on part of our software in order to speed it up. This particular bit was never particularly quick and could appear to hang your machine if you weren't careful so it needed doing. It's not particularly the kind of thing I enjoy though and this had more than a few places to trip me up and come crashing down disasterously. Think I've got it though, it's a vast improvement on what it was before and I've even got another idea to improve it again should I want to spend another week or so on it. Hopefully it'll disappear for the time being - it's one of those things that won't lie down and keeps coming back to haunt me though.