Thanks, I'll try that - I had a play about with that before but clearly did it wrong as I stopped the objects being blit onto the screen altogether
Will take a closer look at it!
I have no idea how you worked that one out but that's brilliant, thanks! I really appreciate that. The only problem is that on Kickstart 1.3 the game just freezes up when loading the music but I can work around that somehow and in any case we're in a miles better position now then we were this time yesterday so thank you