Admin disabling one subscription disables another, which then can not be re-enabled

Hi,

I have defined 3 subscriptions within 2 content types:

1. newsletter (content type: newsletter , opt-in/out method: double)
2. reminder (content type: bulk mail , opt-in/out method: single)
3. anouncement (content type: bulk mail , opt-in/out method: hidden)

A registered user has no access to the subscribing/unsubscribing to the anouncements, but he does to the other two.
Whenever the user enables/disables one of those two subscriptions himself, all goes well.

However, when I as admin change one of those two subscriptions in his name, the third "anouncement" is also unsubscribed, tagging along with the other one! This happens with both others, being of different content types.

Furthermore, after that, I am also, as admin, not able anymore to enable the anouncement subscription, whatever I try. The only way I can then enable it again, is by temporarily change the opt-in/out setting to single or double of this subscription, then return to enable it, and then change the setting back to hidden.

it seems there is a mixup in referencing, causing an extra update query to be executed on another subscription than intended, which is quite problematic. But it only happens when I as admin administer this, not when the user does.