Hi,
Microsoft Dynamics CRM (v4.0 or 2011 - you didn't specify) does not include scanner integration out of the box so you must either have build something custom or are using a 3rd party product which integrates to MSCRM.
So it is fair to assume that the error which you are receiving is an issue with your custom / 3rd party sofware.
Rob
Microsoft Certified Technology Specialist (CRM) GAP Consulting Ltd Microsoft Community Contributor Award 2011