As of PostgreSQL 7.0beta3 running on RedHat Linux 6.1 (with locale disabled in the OS by removing /etc/sysconfig/i18n), I only get one failure in the regression test -- geometry.

If locale is being used, alot of the tests fail.  Sometimes installing to a nonstandard directory will cause them to fail.  And the parallel tests are pretty finicky.

E-mail me your regression output and diffs (regression.diffs in the regression test dir), and maybe I can help.  Knowing what OS and platform would be helpful.