No, that is not correct behavior. It indicates that you did not properly RO mount the drives at some point. You need to:

1. Do this.

2. In the future, make sure that third party programs such as Empacman and GPSapp aren't alive and running from /drive0 whenever you try to mount your drives as RO/RW or whenever you synch. This is a common reason you might be getting unexpected needs for disk-checks because the drives didn't get properly remounted. The easiest way to make sure these apps don't run when you're working on the drives is to only run them in @DC mode.