unable to login in safari

Hi,
in the newest beta .72 (downloaded 9/2/03)
and using the mac os x browser Safari
I cannot log in to the administration section as any user other than the primary admin.
I’ve deleted all wordpress cookies and still no-go.
All of the users I’m trying to log in to have the correct priveleges (at least admin level 3)
Additionally, I get a “Error: wrong login/password” BEFORE I’ve entered a login/password.
Using IE 5.2.2, I can log in and log out of multiple identities (I’m setting up numerous identities on an intranet) and everything works as expected.
Any ideas for me?
Thanks,
Ben