texmacs keyboard shortcut woes

[nsahoo]

I am having some trouble with the keyboard shortcuts in texmacs.

in the math mode, i.e. after typing $, when i move my mouse over square root symbol, it says the short cut is A-s, when i press alt-s it types a sigma in greek. this is just an example, none of the math mode shortcuts work for me, like S-F5 S for summation sign, it doesn't come up, just prints a S when i type Shift+F5 and then type S.

any help?

Thanks