OK, previously I posted about having issues with connecting web parts in 2013 without using the 'Server Render' option. I now know its a little more specific.
I've finally had a bug registered for this by Microsoft. It took nearly 4 months mind you.
The issue is in fact only Task-based List Templates that cannot connect with other web parts when using client side rendering. It seems that with the new features built into the CSR for the Tasks lists, they forgot to add the code to make the connections framework work. I'm hoping its a simple case of adding some JavaScript to get it to work. I haven't had the time to fish through the csr code to see if this is the case.
