Error occurred in deployment step ‘Activate Features’: Feature with Id ‘’ is not installed in this farm, and cannot be added to this scope.

I am upgrading a RSS reader web part used in our MOSS farm for use in the new 2010 MSF farm.
I had it almost complete but could not get it to deploy and activate without an error.  The error message:

Error occurred in deployment step ‘Activate Features’: Feature with Id ‘<GUID>’ is not installed in this farm, and cannot be added to this scope.”
Would come up each time I deployed the feature.

This issue was driving me crazy until I found Graham Alltoft's post:
- http://alltoft.wordpress.com/2011/06/13/sp2010-error-occurred-in-deployment-step-activate-features/

Solution: 

Use powershell to activate the feature not VS 2010

Set the project to No Activation

Deploy from Visual Studio again with no activation this time

Open powershell

Install-SPFeature <yourFeature>

Enable-SPFeature <yourFeature> -Url http://yoursite.com

or

In central admin go to the solution management and activate the solution with the GUI