[MonoDevelop] Parallel mono install - MonoMac - This application requires the Mono Framework

[Robert N]

Xamarin Studio Version 5.9.5 (build 5)
Mono JIT compiler version 4.0.3 ((detached/429313d Mon Jul 13 17:39:11 EDT 2015)

I am working on some older projects that are MonoMac based and am using a parallel mono to build them. Editing/building is a not a problem, but debug running causes a dialog to popup:

Could not launch XXXXXX
This application requires the Mono Framework.
Please download the latest version, .... 

If I build with my parallel SDK and then switch to the Framework based 4.0.3 the application launches via the debugger. Switching the active SDK for editing, building and running is getting old fast :-) 

Is there any solution to this? Am I missing something in my parallel build that causes this? 

Thanks in advance for any help,

Robert