Deployment stumped

[Techno]

I seem to be running into a problem creating a web setup project and making a deployment. never had this before!

I have 4 Project files:

Common
BLL
DAL
MainSite


MainSite has a reference to common and BLL
BLL has a reference to DAL and common
DAL has a reference to Common


when trying to add the source/content/primary output files into the Web Application Folder, and build the project I get this error:


Error 1 An error occurred while validating. HRESULT = '80004005'



Funny thing is, if I take out the Primary project output files and just leave the content and source files for the MainSite, the error goes away, builds but DOES NOT copy the DLL's into the bin directory.....


This ONLY happens when adding "primary output from XXXX" (dll/exe) for ANY project

I know its to do with the circular type dependencies I guess, but what workaround is there?

any thoughts?