WordPress MU

Running fresh install of wpmu 2.8.4a

I am running wpmu with subdomain setup and all seems ok with that. This is a fresh install of wpmu.

For some reason, many plugins which worked perfectly with 2.7.1 are now not working with 2.8.4a

This mainly happens when I have to go into the admin for a plugin and change it's settings. (those plugins that come with a settings tab).

Basically if I am in a subdomain and go to edit the settings of a plugin, not all of the plugins but some, instead of returning to the expected plugin settings page it redirects me to the root domain link as
http://mysite.com/wp-admin/?c=1

I have googled the /wp-admin/?c=1 but have had no luck with an answer.

Has anyone come up with this problem before?
I have no idea how to solve this issue, guessing it may be an htaccess issue, but not sure. I am using the standard htaccess file that comes with mu.

thanks

had the same issue, my problem was that I was using the premium plugin supporter with the module that deactivates plugins for non-supporters set as active.