Course completion/"Found more than one record in fetch() bug not fixed yet

We are using Moodle 2.0.3 to support an online Master programme at the University of Dundee and we have enable "Course completion" in our courses to monitor students' progress.

In the last week, we were having some strange error messages when users trying to access resources in their courses such as "service unavailable" or ""Found more than one record in fetch()" when users tried to log in their courses.

After spending so much time trying to find duplicated records or cheking if IIS /php settings were the correct ones, I discovered that it is enabling course completion which is causing the problem.

I know that a similar bug related to "Course completion" (caused by duplicated records of activities) was reported and its status appears as fixed in the tracker, but I think that this bug is linked to that one.