Has anyone been following (and better still, testing), the changes to DBD::ODBC (post 1.23_4)?   

Presumably these were meant to improve the performance of SQL statement preparation for MSSQL via ODBC.

http://www.martin-evans.me.uk/node/65

http://grokbase.com/t/lists.scsys.co.uk/dbix-class/2010/04/dbix-class-new-experimental-development-release-of-dbd-odbc-1-23-4-faster-please-test/14ivt6k2zol4tz753rdh5g3ngi5m

http://search.cpan.org/~mjevans/DBD-ODBC/Changes#___top

Hugh