Hi Michał,
The reason you lose the reference to Plantronics.Devices.Common.dll when you uninstall the SDK is that it is referenced as a local file under %programfiles%\Plantronics\Plantronics SDK
However, when you uninstall the SDK and install full Spokes or Spokes_RT that local file no longer exists, Plantronics.devices.common.dll now only exists in the GAC under C:\Windows\Assembly.
Generally when developing using iPlugin API you need to have the Spokes SDK installed. It is possible however to reference the Spokes DLLs in the GAC by adding GAC references to your project rather than local file references - you can get an addon for Visual Studio to allow that.
Note, in upcoming versions of Spokes the iPlugin API support may change (watch PDC web site for announcements). For this reason the most flexible option today is the COM Service for C++ or C# (requires .NET 4 or higher), or possibly the language-independent REST Service. Furthermore with the C# API you can develop without SDK installed just referencing the Interop.Plantronics.dll that ships also with the runtime. (Note, the SDK install however includes some useful sample code).
Finally the EnableDeviceFilter doesn't seem to serve any purpose.
Thanks,
Lewis.
Message was edited by: Lewis Collins