Your DataSource Mapping, MSAccess must match a type-mapping schema with that name - depending on the CMP spec you are following (1.1 or 2.0), you would need to modify either standardjaws.xml or standardjbosscmp-jdbc.xml respectively. Since a mapping does not exist for Access you should probably copy the SQL Server type-mapping, give it the name MSAccess or whatever you want to call it, and trial it. From reports, that should work for the most part but you may need to modify the mapping if you get any errors.
Entity beans require a mapping table since they must generate dynamic SQL to put and get data from the database. The mapping information helps the entity bean get the SQL and data types correct for the processes.
Thanks a lot for your advice. It worked!