WordPress MU

I'm not sure when this problem started, possibly between upgrading from 2.9.1 to 2.9.2.

I can't activate plugins site-wide. They worked fine before, but now I can't activate site-wide at all, it just says "plugin active" and it's only activated on the main site. Contact Form 7 and Global Translate are the main ones I need to activate, but also Lightbox 2 just to test.

Once a plugin is activated, the "activate sitewide" link goes away. Deactivate it, and it should show up so you can then activate it sitewide.

I know, it won't work. I click on the "Activate site-wide" link and it behaves like the regular activation link, only activating on the main site, not on any others.

happens the same for me. My installation is fresh from latest and after some time i lost Site_admin recognition.
I can administrate the site, i'm WMPU main admin but the function is_site_admin does not recognice me as site admin.

Also i can't install sitewide plugins. The tables in WPMU looks ok and my tag in site_meta is ok also.
Not cache, not sitewide plugins working.
Tried in firefox and Ie same bug. Also checked that is not a problem with cookies. ¿Looks like some files my get corrupted? ¿Any idea?
The functions i've seen afected are activation plugins sitewide and is_site_admin() does not recognice me as site_admin.

Ok i found the fix. It's not a problem from the WPMU i found in my case is from w3 total cache. It installs a couple of files in wp-content that avoid us to register sitewide plugins. It's not enough to unistall the plugin, you have to delete all files installed from wp-content.

REgards!!

I had similar problem. And it was same plug-in "W3 Total Cache", after disabling this plug-in it is OK. Thanks.