I have the same 30 tables on SQL Server 2012 and also on SQL Server 2000. I first setup an ODBC connection to the SQL 2000 and I can open all the tables in Access.
When I change the ODBC connection to the SQL 2012 server I an unable to open 4 of the tables. The remaining 26 open fine. When I attempt to open any of these 4 tables I get a popup window stating:
"The field is too small to accept the amount of data you attempted to add. Try inserting or pasting less data."
I even created a query and tried to pull just the top 100 records from that linked table and got the same error. Even tried to query just one column (non-indexed) and got the same error.
Some of my tables have 900,000 records and they work fine.
Both Access 2010 and SQL Server 2012 are on the same Server 2008 R2 box.