So the WWF tools for VS.NET 2005 have some 'issues' that can rear their head as strange build errors.

The symptom is that your solution, which has no syntax errors at all, sometimes fails to build and just spouts random bollocks.

What seems to be happening is some wierd caching of types by the designer- reason being is that the designer has to build your custom activities at design time so that you get a nice design experience.

So here are a few tips if you are seeing wierd build errors.

#1. If you are closing VS.NET and/or your solution, make sure that all designer and code documents are closed.

#2. If it's behaving strangely have a crack and building some of the key projects (communication service interfaces, services and activities) individually.

3#. If none of that works, close all your documents, close VS.NET, reopen and rebuild the solution as soon as you re-open.