Oracle and VB.Net: Could not load file or assembly Oracle.DataAccess

Question

Hello I'm having a problem with VB.Net and Oracle.
My problem is as follow:

I had two projects. One of them was made for someone else, He was using Oracle 10g, and his project is a Class Library  project, which had a reference to Oracle.DataAccess.dll Version 10.1.0.200.
Then I wanted to re-use his code, so I added his project to my solution. But I'm working with Oracle 9i and It didn't work, so I change the Reference from the project that I wanted to use, from the Oracle.DataAccess.dll Version 10.1.0.200 to the Oracle.DataAccess.dll Version 9.2.0.700.  But when I try to use the code where It has a declaration like: "Dim objConn As Oracle.DataAccess.Client.OracleConnection" it raises the next exception:
"Could not load file or assembly 'Oracle.DataAccess, Version=10.1.0.200,
Culture=neutral, PublicKeyToken=89b483f429c47342' or one of its dependencies.
El sistema no puede hallar el archivo especificado."
None of the projects have a reference to the Oracle.DataAccess 10.1.0.200 and I don't know why ask for it!
If anybody can help me I will really apreciate it.
Thanks in advance.

Douglas.