Anydvd from slysoft.com
Runs in the background
Lets you remove the RPC
Quote from the help page
"Region Code: Usually you do not need this function. The needed Region Code is always automatically adapted. But there are special cases (especially with US American DVDs) where the automatic selection doesn't work. If this is the case, please look for the Region Code on your package and insert it here.
Feature Removal: You can remove certain features, like Region Code, Analog Protection and User prohibited Operations (like forced Subtitles)"