Taxonomy terms assigned to a node get moved back to original vocabulary if associated with a node and saved

So......Term A lives in vocabulary A. I go into taxonomy manager and move Term A into Vocabulary B. Term A was also connected to a node that has field_vocabulary_a and field_vocabulary_b. If i edit the node Term A it is still associated with field_vocabulary_a in the node edit form instead of field_vocabulary_b. If the node is saved then Term A gets moved back into Vocabulary A.

This seems like a tricky issue to over come and I'm still brainstorming on the best approach, but wanted to throw it out here incase anyone has an idea. The best Idea I have at the moment is that taxonomy manager would have to look thru all taxonomy fields that are associated with the specific vocabulary and move the record to a field associated with the new vocabulary. But even this doesnt seem ideal as it could cause problems if there are multiple fields with the same vocabulary associated with them.

Thoughts?