Login Problem coz of Cookiedomain and Cookiepath

[truthaddict]

Hello ,
I have installed forum on my site:
http://www.mysite.com/forums/

and I have also installed the forum in subfolder say http://www.mysite.com/testing/forums

but the problem is when I am logged in on live it does't allows me to get login on testing thats why I changed the cookiedomain and cookipath so that cookies of live and testing will be handled differently, after changing that forum never allowed me to get login on testing even in admin, so I have reverted the changes from backend by setting the values of cookiedomain and cookiepath in "setting" table, still its not allowing me to get login.
current values are :
cookiepath : /
cookiedomain:

Am I wrong some where?

[Steve Machol]

Leave the cookie domain and path alone and use the cookie prefix in config.php instead.