How can one addin influence another?

So I have written two addins using the community templates.

If I have the first one registered it is preventing the second one I am working on from connecting.

It will hit a breakpoint on a field in the class when I debug, but the OnConnection event never fires.

If I unregister the first on then the one I am working on runs fine.

Each addin has a unique Guid and ProgId. The class names and namespace names are also different.

Any suggestions besides psycotherapy?