Hi,
Since you are using Vault 2008, this might not help. But I thought I'd pass this information.
Please refer the following URL.
http://mfgcommunity.autodesk.com/blogs/blog/view/5/_3/
However, if you are looking for alternate solution, I would suggest you to take a look at the attachment. I used a custom tool button that would invoke "Get latest version" and "Update Assembly".
Hope that helps.
Regards,
Madhan
Madhanagopal Thiruvenkatachalam
Principal Engineer
Engineering Escalation Team
Autodesk, Inc.