If you are using Joomla 1.5 you can avoid the permission issues and Owner 99 being discussed here and in other threads on this Forum by simply enabling the FTP Settings in the Global Configuration and Joomla will then use FTP for all its updates and installing and you can have all your permissions set to 644(files) 755(folder/Directories). No more failed installs of extensions because of permissions and no more fiddling with FTP clients to give all the folders 777 permission.
1. Set Up FTP Account in your cPanel.
You can use your default FTP account, however for better security I suggest you set up an FTP account just to be used by Joomla and call it something meaningful. Select cPanel icon FTP Accounts and enter the following.
Login: Joomla @yourdomain.com.au (I have used joomla but the name can be anything)
Password: whatever you like but you need to remember it for later.
Directory: /public/joomdir (Joomdir needs to be the directory where Joomla is installed)
Click Create FT account
2. Update Joomla with FTP details.
Select Global Configuration and then the Server tab so that you see 'FTP Settings' in the bottom left corner and enter as below.
Enable FTP: Yes
FTP Host: 127.0.0.1
FTP Port: 21
FTP Username: firstname.lastname@example.org
(or whatever you entered in Step 1)
FTP Password: (whatever you entered in Step 1.)
FTP Root: (Leave blank as we set the default directory as joomdir in Step 1.)
Now Save or Apply the settings.
If you have permission issues and cannot save the FTP Settings, open file manager in cPanel and edit joomdir/configuration.php and you will see the FTP settings. change the 0 to a 1 to enable them before you save it.
If you look in the System Information box you should see all directories(excluding CACHE and TMP) as unwriteable. This is okay as FTP is going to do the writing and not Joomla
Using cPanel File Manager or FTP Client change all the permissions to 644 for Files and 755 for Directories(777 for /cache and /tmp).
If you still have extensions or what not with owner 99 either ask Unlimited Tech support to change them or what i did was to disable the FTP settings for moment, uninstall all the offending extensions via Joomla dialogues, turn FTP settings to enabled and then reinstalled everything correctly.
If you are doing a new install of Joomla, do Step 1. and set up the FTP userid first and then when asked during the install you can enter the information as described in Step 2.