Can't log in after upgrade to 6.25. Please help!

I just upgraded my site from D 6.24 to D 6.25 using drush and am now unable to log in to the site. I have uncovered two facts:

• Sessions are not being created for anonymous users
• The sid in the database does not match the cookie value being set in the browser (but it should)

I'm unsure where to go from here and any help would be appreciated.

Additional info:
Along with the core update, the following modules were updated:
computed_field
google_fonts
remember_me
simplemenu
webform
rubik
tao

My first thought was that remember_me might have done something, so I disabled it using drush. With no luck, I also uninstalled it. I also tried re-installing the previous version.

I also tried setting the domain cookie variable in settings.php without luck.

Here are the session settings from php.info:

Session Support => enabled
session.auto_start => Off => Off
session.bug_compat_42 => Off => Off
session.bug_compat_warn => On => On
session.cache_expire => 180 => 180
session.cache_limiter => nocache => nocache
session.cookie_domain => no value => no value
session.cookie_httponly => Off => Off
session.cookie_lifetime => 0 => 0
session.cookie_path => / => /
session.cookie_secure => On => On
session.entropy_file => no value => no value
session.entropy_length => 0 => 0
session.gc_divisor => 1000 => 1000
session.gc_maxlifetime => 1440 => 1440
session.gc_probability => 1 => 1
session.hash_bits_per_character => 5 => 5
session.hash_function => 0 => 0
session.name => PHPSESSID => PHPSESSID
session.referer_check => no value => no value
session.save_handler => files => files
session.save_path => no value => no value
session.serialize_handler => php => php
session.use_cookies => On => On
session.use_only_cookies => Off => Off
session.use_trans_sid => 0 => 0

The two lines that appear to differ from another post I saw are session.use_only_cookies and session.cookie_secure. But it is worth noting that these settings worked fine before the upgrade.

Please help!