A key (which one?) changes the letters all keys type

Hold down the "code" key, the one to the left of the spacebar that says "CODE" on it, and hit the "L" key (the one that says (Lang) on it. Should be back to normal.

You may have unwanted debris under the keys. Turn the keyboard upside down and brush gently between the keys. If the problem then affects another key you know you are on the right track - the debris is moving around.

You have activated the number lock on your laptop to unlock press the "fn" function key and 'NumLk" key that should get it back to normal

Examine your keyboard for any build-up of dust, dirt, liquids or other particles that could be causing the keys to type the wrong characters. Allow any loose dirt to fall out by inverting and shaking the keyboard lightly.
Confirm that your keyboard is set to the English language. Go to your control panel and click on the "Regional and Language Options" icon. If the setting appears to be in a foreign language, change it to English/U.S.
Check if your number lock key is on. If so, depress the key to disengage it.
Run a character key test by using the Microsoft Keyboard Diagnostics (MSKEY) program. While in the MSKEY program, hit several keys to make certain that they are the same keys that are identified in the MSKEY window. To start MSKEY in Windows Vista, select "All Programs>>Accessories>>Run" from the Start menu. Type "mskey" in the box and depress the "OK" button. Start MSKEY In Windows XP by clicking on "Run" from the Start menu. Type "mskey" in the Open box, then hit "OK." Depress either "PS/2" or "USB" to apply it to your type of keyboard hookup. MSKEY software is only available with Microsoft IntelliType version 1.1 or later.
Remember to clean your keyboard regularly to keep it free of dust and debris.
Don't disassemble the keyboard because it may affect the validity of your manufacturer warranty!

Usually you have to hold the "Fn" key to get to these. Look for a "NumLock" key to turn this off. You may need to use the "Fn" key to select numlock.

you will need to replace the daisy wheel to resolve this issue,

You need to press the NUM Lock key.
The NUM lock key is usually the same key as the ScrLk key but to select the NUM lock you need to press and hold down the Shift key and then press the NumLk/ScrLk key. A LED light will light up to indicate the number keypad is on.

Well, this happens alot, it is usualy because you are not hitting the right buttons, the keyboard is small and anyone can make that mistake. Sometimes when you pres T you might acidently hit Y. So, just be more careful when typing.

That did it....I didn't know there was a screen calibration tool on it. Thanks for the assist!

have you tried to change the TEXT T9 from iTap to just ENGLISH