Hmmmmmm. . . .I have managed to recreate it in at least one instance. If I open up an app called Terraterm Secure Shell (text-only terminal/telnet kinda thing). . .it toggles the numlock to On when it opens (leaves it On if it's already On), but when I enter the email program, Pine, it toggles it to Off.
That's not the only app it does this on though.