Unable to edit this file. Could this file (or the form entry this file was generated

System

Hi,

I am using teamsite 6.5

I have some pages which are showing the following error when i tried to edit.

Unable to edit this file. Could this file (or the form entry this file was generated from) be locked by someone else or in another workarea?

I dont know how to unlock this file.All these files showing this error message are created using Webmaster Role.I have unlocked many times all these files.But still when i use author or editor to edit this page, i am getting this error.Is there an way to solve this problem.Kindly advise.
Thanks

Regards,
Leoh