Try this:
Login to http://x10hosting.com/control/login.php with forums username and password.
Go to "Hosting" on TOP navigation, ----> Then Click on "update password". There you can change your password. put forums password in "Current Password" field.
Note: After this process, password for your client account, cPanel, and forums will become same.
Then try login to cPanel again.
Thanks for your quick response, the problem fix now.
I am reset my password through forgot password (https://x10hosting.com/control/login.php), coz when I am trying to change password the system always ask old password and always failed.