http://support.microsoft.com/kb/913764/
The KB article didn’t say a lot of details about this bug. Usually the following conditions have to been met in order to trigger the bug:
1. Query must run against sql2000 (Sql2005 works fine)
2. The table name has to include 3 or more dots, ie: [A.B.C.D.E]
3. There has to be an image, text or ntext column in the table
It has something to do with the way we parse table name in SqlClient and the above KB article has provided a fix.