Keyboard problem-iMac OSX 10.4.7

[tls]

I have a slight keyboard problem. I have a wireless Apple keyboard and I use Apple+A for 'Select All' frequently. But suddenly the sequence doesn't work! I can go to the Edit menu and 'Select All' and it works fine. I can highlight pieces of the page, the A key works, every other Apple key sequence works, but the Apple+A for 'Select All' doesn't work! I've searched the OSX Knowledge Base documents, the Help file on my computer, cleaned the keyboard, even changed the keyboard to a USB wired keyboard and searched the various forums and there is nothing about my problem.

This my last hope!

[simbalala]

Check Preferences -> Keyboard and Mouse -> Keyboard Shortcuts to see if you've inadvertently reassigned Command A.

[tls]

Thank you simbalala! I was over-thinking, as usual, and I missed the basic! <Blush!> Apple+A was set for "Turn full keyboard access on or off",
whatever that does. I've only been using OSX for less than a year, and I still haven't figured a lot of things out!

Terri