Shoutbox

Can someone tell me why can't i send quick text that i have set with (ALT+1,ALT+2,ALT+3,ALT+4,ALT+5) if i try with ALT+6 or up it's working fine.
Any idea, bug or something else, i'm using xp professional with sp2, i have the same problem one time, but after restore settings it was fine again, but this time, nothing change, i made a unistall, reinstall,etc and it remains.

Thanks guys.

Are the ALT+1-5 shortcuts used in other programs or in Windows itself? If so, that's the source of the conflict.

Thanks anyway, i found a problem source.
It was a keyboard.