Please provide a bit more information on how the owner granted the permissions to the user and what permissions were granted. also describe what happens when the user tries to access the site and we'll try to help.
Paul Stork SharePoint Server
MVP Senior Solutions Architect: BlueChip Consulting Group
Blog: http://dontpapanic.com/blog
Twitter: Follow @pstork
Please remember to mark your question as "answered" if this solves your problem.
