The wizards do not allow you to specify an owner. So, if you are not logged on as the object owner and the object is not owned by the DBO, the wizards will not find the object.
Use sp_changeobjectowner to change the owner of the table to the DBO, and then run the wizard again.
Microsoft has confirmed this to be a problem in SQL Server 7.0. This problem has been corrected in U.S. Service Pack 2 for Microsoft SQL Server 7.0. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
254561 INF: How to Obtain Service Pack 2 for Microsoft SQL Server 7.0 and Microsoft Data Engine (MSDE) 1.0
For more information, contact your primary support provider.
One example of this problem is that when you run the Index Tuning Wizard on tables that neither you nor the DBO own, you will receive the following error:
The server returned an error attempting to either create a temporary table or index statistics.
Another example of this is that when you run the Create View Wizard and use tables that neither you nor the DBO own, you will receive the following error:
Error 21776: [SQL-DMO]The name '<object name>' was not found in the Tables collection. If the name is a qualified name, use  to separate various parts of the name, and try again.