Intermittent Time Out Errors

We recently migrated a SQL 2000 DB to SQL Server 2005 SP2. We have a VB 6 executable that uses the SQL Server 2005 DB. Immediately we began getting intermittent errors when trying to run a Stored Proc on SQL 2005 DB. The two errors we see are:

Timeout expired

[DBNETLIB][ConnectionOpen (Connect()).]SQL Server does not exist or access denied.

If you immediately try to run the same query, it usually will work. The queries are random and so are the errors. I have gotten the time out error in Server Management Studio a couple of times.

In the VB 6 App we are using MDAC 2.81. Her is the connection string:
Provider=SQLOLEDB.1;User ID=user;password=password;Initial Catalog=OASIS;Data Source=servername, portnumber

We added the port number to the DataSource in an attempt to troublshoot the issue, but it made no difference.

We have run sysinternals Process Monitor on a PC with the app running and we saw NAME NOT FOUND Results for Query Open actions for these DLLS:
C:Program FilesOASISCLUSAPI.DLL
C:Program FilesOASISRESUTILS.DLL
C:Program FilesOASIS
tdsapi.dll

C:Program FilesOASIS is the application path. Of course, they are not in the application path but they are in C:WindowsSystem32. They do not seem to be registered.

Here is an example of the code we use in a class to run a SP:

Public Function FetchPostings() As ADODB.Recordset
Dim cmFetch As ADODB.Command

On Error GoTo HandleError
Set cmFetch = New ADODB.Command
With cmFetch
.Name = "FetchObligations"
.ActiveConnection = gobjSecurity.Connection 'This is a connection string not a connection object
.CommandText = "spClaimFetchObligations"
.CommandType = adCmdStoredProc
.Parameters.Append .CreateParameter("ClaimID", adInteger, adParamInput, , mlngClaimID)
Set FetchObligations = .Execute
End With

ExitSub:
Set cmFetch = Nothing
Exit Function

HandleError:
gobjError.HandleError Err.Number, Err.Description, App.EXEName, "clsClaim", "FetchObligations", gobjSecurity.UserID
Resume ExitSub
End Function