Compile project holding reference to another

[kina]

My project has two .vbproj (Data and Businnes)and one .sln file (MyProj)

I compiled Data and MyProj ok; Business is failing.
Business object has reference to Data.
It complains about all references to Data:
C:\netvss\Business\CBOClass.vb(165) : error BC30002: Type 'CDOSAgreement' is not defined.
CDOSAgreement is a class inside Data project.
I am using VS 2002; framework 1.1