Cannot See My Ubuntu Desktop from TeamViewer on Windows

Hi, 

I have Teamviewer installed on 3 Windows desktop PCs, 2 Windows laptops  and a single Ubuntu desktop machine, all on my home network. I have an odd problem however.

I am logged onto all of the above systems using my single Teamviewer account. From the Ubuntu desktop machine, I have all of my Windows PCs and laptops displayed in the list of computers available. However, none of the Windows machines display the Ubuntu desktop machine as an available computer.

Any idea what could be wrong or what I'm not doing properly?