Lines 131-171 of DataDataStoresEditorAction.java grab a 'new' datastore with the same params as the old one, get a layer list and then dispose of that datastore. Unfortunately, ArcSDE has a static hashmap behind the scenes and when the 'new' datastore is dispose()-ed, the original is also closed down. Not sure how to get around this...perhaps passing a flag to 'force a new store' that was correctly handled by ArcSDE would be enough.