Oracle connection from VB6

Hi,

I'm trying to connect to an Oracle Database from a form written in VB6
Command I'm using is :-

Set goOraDatabase = goOraSession.OpenDatabase(sDBName, sConnect, ORADYN_DEFAULT)

This returns an error and I get a 440 error message returned.
I've taken the details in sDBName and sConnect and used them to manually connect to the database using Toad and
this works fine.

A few other people can run the form and connect with no issues it's only my setup that seems to be the issue so I must
be missing some part of my setup but I'm unsure where to check for this.

Any assistance appreciated.