I need to press F10 for entering a program option (openMSX), but I'm lost. I've tried modifying keymaps and modmaps with no luck

I haven't found the way either witht the zaurus keyboard or an external USB keyboard.

Any clue?

You should be able to do it in your Xmodmap (assuming it's being loaded). Does changing other keys work?

Yes, changing standard letters work perfectly.

I supposed that pressing "Fn" + 1-0 would send F1-F10, but it doesn't. Is that the correct key combination?

Thanks

In your Xmodmap, you should have lines something like these (keycodes are random and almost certainly not correct):



The point being that the columns go normal press, shift press, Fn press, Fn + Shift press.

Does that help?

Yes, I have those lines in xmodmap. I'm using that Jaunty zubuntu install.

I've even tried to put "F10" at those positions on all the number keys, unsuccessfully.

Finally. I had to map it to the right shift key. But of course I can only access F10. Unfortunately, openMSX on the zaurus is too slow to be usable at the moment.

I guess Xbindkeys has something to do with this problem. But even if I kill it, function keys still don't work.

And all the other Fn key-combos work fine? I'm out of ideas then.

nope, no funtion key work at all. Do they work for you?