Acts_as_taggable not loading in dev environment?

It seems in my development environment I keep throwing:

undefined local variable or method `acts_as_taggable’ for Item:Clas

Indicating that the acts_as_taggable pluggin is not loading, yet in my
test
enviroment I can run tests against act_as_taggable methods for that very
same class just fine.

Has anyone else experienced this?

Tim C.
[email protected]