I have been using VS / SharePoint / Communicator (and Lync) together for several years and have never noticed this problem.
I would suggest that this is due to the integration between Team Explorer and Communicator - if you exit the "Members" option within the project, you should see the presence of all the users defined for this project.
If you do not use this integration (to be honest, it never added any value to me), you can disable it by right-clicking on the “Members” option and then selecting “Personal settings”. On the General tab, in the Collaboration area, select Change ... and select None as the provider.
Otherwise, I would suggest a not too complicated option to remove and reinstall the device ...
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