When you say 'arrow button', please be aware that the 7500 has a 4 way cursor on it and I especially confused that with simple onscreen arrow buttons that you created.

Why is this important? Because the 4 way cursor can be turned off via a firmware such that it will only control remote page/device navigation.

Please post the IR code data and the source of the data (how you got it) for the codes that don't work.

I suspect these are toggle codes (see the Classic Pronto faq if you want to know more).

Thanks,
Lyndel