Buddy, spre some 'a's?

So, friend of mine is running pre-relese version of Mc OS X 10.3 (“Pnther”) nd is hving some inexplicble trouble with his keybord in which he cn produce cpitl ‘A’ but not the lowercse version of the populr vowel. Neither he nor I hve clue how to begin troubleshooting this isse, so ny dvice would be extremely welcome. Thnk you.