Fusion Middleware control 11g giving error "Because of inactivity, your session has timed out and is no longer active. Click OK to reload the page."

I have a setup where two weblogic domains are created on ports 7001 and 7002 for FMW11g PFR&D.

When I try to access EM 11g FMW control for both the domains concurrently I started seeing this error.
I created Oracle support ticket and analyst informed me that its a known bug 8305372 which is scheduled to be fixed in 12.1 version. The cause of the issue is because of how the cookies are used by the browser.

There is some workaround suggested by Oracle Analyst :
Use different browsers for each connection
for example
use Firefox to access domain1:7001
and use IE to access domain2:7002

I tried that workaround and it works. Also I tried below:

FOR IE:
If two tabs are used , I am getting same error. But if I use two separate IE windows, I am not getting error.

For Mozilla FF:
Both for two tabs or separate windows I am getting same error.

Bottom-line is if you get this error while accessing two em setups on same machine then you can try using either separate browsers or separate IE windows as mentioned above.