In versions prior to 2.8, extensions go in the /tce directory. From version 2.8, extensions go in the /tce/optional directory.
The owner and group of the /tce and /tce/optional directories should be tc:staff.
To change the owner and group, open the terminal and type:
sudo su
cd /mnt/hda1
chown tc:staff tce
cd tce
chown tc:staff optional
If you are using a partition other than hda1, change that as appropriate.
With version 2.8, you need to set up OnBoot and OnDemand.
Open the Control Panel. Click Apps Audit, OnBoot, then Maintenance. Click on extensions on the left side, you want to be automatically loaded when you start the computer. Do not click on dependencies. They will be automatically included.
Still using the Control Panel, click OnDemand. Type the numbers preceeding any programs you do not want to be loaded when you start the computer, but to be available from the OnDemand menu. Do not click on dependencies. They will be automatically included.