That just sounds like you need to have the Exchange 2010 Admin Tools installed on whatever system VisualCron is on. There might be an optional component (we're not on 2010 yet... can't validate) to install, though i'm pretty sure Exchange 2010 cmdlets are installed along with that.
Obviously, the exchange cmdlets are not native, so i'd lean towards an Exchange admin tools install corruption on the system running VC. VisualCron wouldn't (at least I can't think how) be at fault or even involved here. The scripts and/or code should work outside of VC. I assume thats been tried, manually running the scripts and excluding VC from the issue?