It's running

Looking great!
Well, it is only running in windowed mode.
If I try entering full-screen mode via options panel it crashes

Looks like the frequency setting is kind of invalid.
That's good news! Even if I'm unsure how come it works now when it didn't before...
The main thing I changed is that I use a pre-built version of SDL.dll now instead of one I built myself - but I've no idea why that would cause it to go wrong only on some machines

The fourth number isn't the frequency; it's actually a flags bitfield (which I stupidly printed out as decimal, making it look rather odd.)
In hex, that number's 0x80000003 which is SDL_FULLSCREEN | SDL_HWSURFACE | SDL_OPENGL. The refresh rate is unspecified, so it should just go to the monitor's default.
So it's just asking for a 640x480x32bpp fullscreen surface - which should be pretty standard, I thought!
ok I've put up my window init code
here, theres some redundant stuff but you could look for descrepencies between our code:
Thanks! That code's
really similar to what I'm using, except I set the SDL_HWSURFACE flag.
Thinking about it, that probably doesn't do much for opengl surfaces anyway - presumably they don't default to SW!
Oh, and your code is a lot tidier than mine