It may be hard to believe but not all the prices for an outlook signature are stored in the same place. Out of the box if your using ProfileUnity from Liquidware Labs you need to change or create a new Portability setting. I have chosen to add rules to the Office Potability Rule set.
Registry Rule: Replace Tree software\microsoft\windows nt\currentversion\windows messaging subsystem\profiles
Filesystem Rule: Replace Application Data Microsoft\Signatures