Thanks gep.

no 3rd party tools in the project. the build order is also fine.
its to do with circular dependencies and how the deployment project behaves.

The work around is as follows:

split the solution in 2.

solution1: just the website project and the setup/deployment project.
solution2: just the class libraries (common, DAL, BLL)

then in solution one, just add the BLL/DAL/Common assemblies into the project

job done.