When editing pages which have the Rollout checkbox (but not the Rollout modules page) I get the following error:

# warning: Missing argument 1 for rollout_apply_settings() in D:\www\sites\all\modules\rollout\rollout.module on line 48.
# warning: Missing argument 2 for rollout_apply_settings() in D:\www\sites\all\modules\rollout\rollout.module on line 48.
# warning: array_keys() [function.array-keys]: The first argument should be an array in D:\www\sites\all\modules\rollout\rollout.module on line 62.

And the function exits abnormally. This can result, for example, in the creation of duplicate vocabularies.