Woooh no need to panic.
HTC smart dialer is the app that suggests contacts while dialing the numbers.
If you had the original dialer pad then you probably already had it.
You might have some luck if you install a dialer pad skin to the device as well as the smartdialer.cab. I would assume that the smartdialer.cab didnt include any skins for the dialer leaving it white but it did overwrite the original. If you get what I mean.
Try this skin. Its the basic one from the touch that would include smartdial. So Im pretty sure you wouldnt even need to install the smartdialer.cab. Just make sure you uninstall from the sd card first (might still have the messed up dialer, dont worry)
http://www.freewarepocketpc.net/ppc-...aler-skin.html
If you cant get that to work it might be easier backing everything up and hard resetting. If that dont work with the other dialer Ill point you in the direction of some programs for that.
The Schaps Advanced Utility program can be found here. All I did was google.
http://forum.xda-developers.com/showthread.php?t=317070