it is too funny, here is my answer
Hey if you can not see the copyright below , i changed and added footer and wrote phpBB Group copyright information but
after i click purge cache under site administration, it doesnot show copyright info too. At local computer it is fine, the files worked but at live site it is not.
By the way you are not going to give support again because you do not see the copyright below!! and i do not know how to show it.