I'm running fml-universal-3.1.35.394 with AutoSwitch v2.3.0 and have this same exact problem,
EDIT:
Interesting, when I run the mod with Risugami's ModLoader it works fine, but with FML it fails.
@thebombzen: I notice ModLoader has no rh.getStrVsBlock, so I'm assuming you're doing some kind of check to see if the user is running ModLoader or Forge, and issue further checks differently because of that. My guess is the use of FML is throwing some check off to think the user is running full Forge, and trying to access the edited rh (which FML doesn't come with).
