Email Error on Internal Install

We are trying to setup an internal blog onto a box running Linux 4 and PHP 4. Everything seems fine up until the actual install step. When hitting the “install wordpress” button on install.php?step=2, we are getting the following error:

ERROR: that isn’t a valid e-mail address. E-mail addresses look like: [email protected]

We’ve tried with multiple e-mail address, but the same error keeps coming up. Any ideas?