The Pg, MySQL, and ODBC DBDs have all been released with fixes. You do not need to upgrade DBI to benefit from them.

The DBI package proper currently has an issue on installations without rubygems; a complete fix is in the works, but for now, you can pull the git repository to get a fix for running DBI, it should (as always) install with setup.rb without incident. If you need to build/test against DBI, you'll still need gems. Once this problem has been rectified I will release 0.4.1, hopefully in a few days.