Guys, thanks very much for your help!
I have sadly lost the file altogether including the temp files, gutting. I'm new to coding so it's probably not a bad thing starting again fresh, I have already got 50% of the code re-done and it's much tidier this time round
I'm also using BlueIDE which is a free alternative to the dark basic's editor:
http://blueide.sourceforge.net/#dl
It has a great "backup" feature that creates a duplicate of your code in a different folder structure, so that if one file does become corrupt/damaged etc There is a second file to fall back on. (just remember to keep pressing it often)
Also, I'm saving my files in to a synced "DropBox" folder so that my files not only get saved locally but also in the cloud!
I'm hoping this time, I have got every angle covered.

Thanks again for all your advice, I tried most of it!
www.bensimms.co.uk