I recently switched to my WM 6.1 (ASUS p527), it is touch screen and has a keypad too. But messaging was quite difficult. Removing the stylus each time is cumbersome, and windows mobile didn’t let me use the keypad the way symbian based mobiles would let me to. I searched a lot, some said there’s some fix, downloaded various keyboard layouts, but wasn’t satisfied.
It’s very simple to turn the windows mobile messaging dictionary.
Go to Start> Settings> Personal> Input.
Set the input method as XT9 and tap on options.
Now uncheck all of them (If u lk 2 typ lk ds [if you like to type like this]).
Now tap done.
And, it’s done!
Simple, no patch needed.
Note: After you do this, it is possible that whenever you start yping a new message, the on-screen keyboard pops up and thus you can only enter numbers using the keypad. And when you hide it and start re-typing the numbers you erased would reappear. There’s a solution for this. Do as I’ve mentioned above and then select keyboard as your input method. This way if you accidently type numbers and erase them, they won’t reappear. 
