Comment 1 for bug 377935

I can confirm all this. To summarize, if you are directly subscribed to a duplicate of a bug but not the main bug, when you look at the main bug, your name is not listed in either direct subscribers or duplicate subscribers. However, the Subscribe/Unsubscribe link says "Unsubscribe" as if you are listed. On clicking the "Unsubscribe" link you are then directly subscribed and listed as a subscriber. After a page reload, the portlet now lists your name in both direct and duplicate subscribers, which is actually correct now.

To fix this, the portlet should correctly list you as subscribed via a duplicate and the Subscribe/Unsubscribe link you offer a "Subscribe" link, not "Unsubscribe."