Something wierd is going on with the way that the Wordpress Admin Bar in WPMU 2.7 writes URL's - specifically for plugins, rather than the default Admin options. At first I thought it was to do with a dodgy plugin, but I'm pretty sure its actually how the Admin Bar (incorrectly) constructs URL's.
For instance, cformsII adds itself to the Wordpress Admin Bar with the following options:
--- TITLE ---
cformsII http://domainname.com/wp-admin/admin.php?page=cforms/cforms-options.php
--- DROPDOWN MENU ---
cforms (repeated from above) http://domainname.com/wp-admin/cforms/cforms-options.php
Global Settings http://domainname.com/wp-admin/admin.php?page=cforms/cforms-global-settings.php
Styling http://domainname.com/wp-admin/admin.php?page=cforms/cforms-css.php
Help http://domainname.com/wp-admin/admin.php?page=cforms/cforms-help.php
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Note that the first and second items in each dropdown should point to the same URL - except it seems not for plugins (see in the example above, the difference between the title URL and the option beneath it - it's missing admin.php?page=
from the URL string). Clicking that second link produces a nasty 500 Server error, as its pointing to an invalid URL.
Looking at the code for cformsII, it appears that WPMU core code is repeating and constructing this second URL and its doing it wrong! Interestingly, exactly the same thing happens for WP-PostRatings plugin as well as others.
Any ideas - I'm pretty sure its a bug, but was wondering whether anyone had any suggestions...