Users getting permissions error when managing subscriptions using the Notifications > Subscriptions tab

My users are reporting (and I've confirmed) that when trying to manage their subscriptions by going to Profile > Subscriptions > Notifications they get a "You don't have permissions to manage these subscriptions" error.

However, they are able to manage subscriptions if they go to any of the more specific tabs. (They are able to manage their subscriptions using the Groups, Tags, and Threads subtabs.)

Authenticated users on our site have the following rights:
NO: administer notifications
YES: maintain own subscriptions
NO: manage all subscriptions
YES: manage own subscriptions

Enabled modules include:
- Content Notifications
- Notifications
- Notifications Autosubscribe
- Notifications Lite
- Notifications UI
- Taxonomy Notifications
- Organic Groups Notifications

Versions:
Drupal 6.12
Messaging 6.x-2.0
Notifications 6.x-2.0

Let me know if I can provide any more info.

Thanks,
Kevin