I bought this keyboard a few days ago because it was cheap at Best Buy (29.99). The drivers for it are terrible (yes even the latest ones) The d-pad mouse thing doesnt work at all so here is a way around that so you have arrow keys, I know it's not pretty but it works. You will still use the drivers from targus.com this will be another layer on top of it.
1. Download and Install AEKMap
http://ae.inc.ru/aekmap.php
2. unzip and copy file (targus keyboard.aek) into /program files/aekmap
3. Run Aekmapsettings.exe - On the first box choose Targus Remap nad hit save. Now run the Targus drivers and youre good to go!
4. Run AEKMap.exe
The software requires that you register and buy, it is a bit pricey but I suppose cheaper than a new keyboard.