Xperia Pro (and other Pro devices of Xperia range) has 14 different key layouts as mentioned on this page. I am releasing a specific update.zip file for each of the 14 different key layouts. Flash the relevant zip for your phone and your hardware keyboard should start working as it should.
To find out which layout is your phone keyboard, go to this page.
If you are unsure about the relevant key layout for your phone, then there is always the tedious option of flashing each update.zip and seeing if it works.
Note 1: I am only releasing 10 keyboard layouts now. I shall release the rest when I get some time to figure it out.
Note 2: This is for Xperia Pro, but might work in other Pro devices of Xperia range. Please confirm if anyone gets it to work on any other Pro devices.
Note 3: If any of the below does not work in your phone or you phone has a different layout than the below, please help me to get it fixed by sending me a PM.
1. CWM recovery installed (or root if you are copying files manually).
1. Download and copy zip file to SD card
2. Reboot into recovery
3. Choose install zip from SD card, select zip and flash .