Internal Server Error After Installing U.B. Plugin

Hi, everything was working fine on my site -- right up until I installed the new Ultimate Branding plugin via the WPMU alert in my WP dashboard. I had a few of the older WPMU, individual branding plugins installed (custom admin bar, custom login image, etc.), so after Ultimate Branding was activated, I was alerted to deactivate the older conflicting plugins. Upon deactivating the custom admin bar, I got an Internal Server Error. 2 hours later, I'm still getting the same error when attempting to load any page on the site. Once, however, I was able to successfully load the WP admin dashboard page. But after clicking "my sites" I received the following error message:
Failure retrieving table data [SELECT count(*) FROM wp_options WHERE option_name LIKE '%wpbusdirman_postform_field_label_%'].

Is this due to the plugin installation, or is this an unrelated issue with the server?

Help! Thanks!