[kh99]

Actually, I was just looking at the delete_user_subscription() function, and it looks like if the user's primary group is not the same one that was set by that (expiring) subscripton, then the primary usergroup isn't changed. There is some other logic, in that function and the build_user_subscription(), having to do with checking other active subscriptions before setting the usergroup, but I haven't worked it all out yet.

ETA: The answer seems to be (if everything is based on changing primary usergroups) that if you buy a tier 2 subscription after buying a tier 1, when tier 1 expires the user will stay in tier 2, then when tier 2 expires you will go back to tier 1 (and as Ozzy pointed out, it appears that it would be permanent unless some other arrangement is made to change it). So, like I said a few posts ago, if you use secondary groups to add the permissions, that should sidestep the issue. And as always, I recommend testing out whatever system you set up to make sure it works as you expect.