ODBC Error in VB.NET after upgraded

I have recently converted my VB6 app to VB.NET.

When i try to open one of my form,i'm getting the following error

[Microsoft] [ODBC Driver Manager] Data source name not found and no default driver specified"

I am using ADODC control and sheidian datagrid control in this form.

The error happens in the following routines,

Public Sub VB6_AddADODataBinding()
       dbgrid1.DataSource = CType(dc1, msdatasrc.DataSource) 
End Sub

When i try to close this form,

Public Sub VB6_RemoveADODataBinding()
       dbgrid1.DataSource = Nothing 
End Sub

I tried all the options by re-installing MDAC, Oracle 9i Client. Do i need to reference anything
Anybody has any ideas how to get round this Your thoughts would be very very welcome because I've been struggling with this for some time.

Thanks,
VKT