Unable to Access the Network Area in Wordpress

Guys,
I have a wordpress installed network of blogs ( 5 blogs ) and quit a lot of plugins. Up to yesterday, everything was going perfectly. But, when i tried to login today with the same username ( edited ), i got authentication error. So, i checked and found that my edited username has magically transformed to "admin" which is wordpress default username. So, i changed the pass and entered using "admin". I opened my profile to edit and as by default i was not able to edit the username. So, i tried to enter the network area myblog.com/wp-admin/network but a message "You do not have sufficient permissions to access this page" is displayed and there i knew, i was degraded from super-admin to only administrator. At that point, i thought if my site was hacked or not. But while checking thoroughly, all the contents and plugins are same.
After that, i disabled all the plugins from Cpanel, thinking if there might be some plugins conflict but still not able to solve this. Either i only have access to primary site and able to publish new posts etc but if i am not able to access network, its not possible to update, add or delete plugins, wordpress itself and other sites under the network. So, what should i have to do to solve this issue? Hoping for quick and effective reply from geeks here..
Thankx in advance!!!

 

Can you PM me some of the domains?