I did as you suggested. Documents were not assigned to a space. However, iTunes, mail and stickies were all assigned to space 1 (where the documents were being sent when I clicked "9"). So, I switched their spaces to 7, 8, and 9. That did not seem to fix the problem.
I changed the option for "To switch directly to a Space" ... Command Number Keys.
But now the 9 key won't do anything ... no 9 appears when it press the 9 key.
I followed your instructions (the Standard US keyboard was selected) ... reset the keys as directed.
Still cannot type a 9 without holding the "alt option".
I was in Word, but the response is the same in Text Edit.
Yes it did work at one time. The only change I can think of is that I downloaded Skype.
Mac OS X 10.5.6 version
Yes it is an Apple brand keyboard (MacBook)
Yes I am using the US keyboard setting in the International Preferences
I was finally able to get the Apple Updata (10.5.7) downloaded and installed. I then moved the Library/Preferences/Preference.plist to the desktop and rebooted. Still did not solve the problem. No 9 can be typed without holding down the "alt option" key.