I didn't try reinstalling because it was a fresh install. I am an admin user. Here are the plugins I have:
Akismet Version 2.5.3
Bad Behavior Version 2.0.43
Google Analytics Version 1.0.2
Subscribe To Comments Version 2.1.2
Text Control Version 2.0b1
WP-Gatekeeper Version 1.5rc5
Yet Another Related Posts Plugin Version 3.3.1
Note, the problem I experienced was with the version of WPTouch that I got from the wordpress plugins site. I purchased the pro version and this doesn't cause the same problem, although it does still seem to have a problem: the settings link in the /wp-admin/plugins.php view leads to /wp-admin/admin.php?page=wptouch-pro/admin/admin-panel.php which has the same error about permissions: "You do not have sufficient permissions to access this page."
The sidebar link in the admin panel works fine on the pro version, however.