Multiple Membership Levels Conflict

Hi, we had a tiered membership site that was working great and now we want to add a new level, but have had some difficulties.

Our set up:
1: visitor level (access to home page and sign up pages)
2: basics level (access to a basics program)
3: advanced level (access to an advanced program that includes the basics program)

We want to add a 4th level that is completely separate. So, if a user subscribes to this level then they will get one page of content. I have done this, but the issue is that when I set the rules for this it cancels out the settings if they are already subscribed to one of the other levels. I've tried both the positive and negative rules. It seems that the levels are conflicting. So, if a user is subscribed to level 3 and adds level 4, then they no longer have access to level 3. Suggestions for how to set this up without that conflict?