No idea where the other posts of yours are.
I've just read this one.
There is a setting in each tracker denition to be used in conjunction with the param view=user, in order to make that a user can see just his own items.
Please, open a wish in http://dev.tiki.org , and create a "Show" instance linked to it where you reproduce your issue. This way it will be easier to teach you how to set up your tracker in order to let you achieve what you are looking for.
The future Upgrade wizard (in trunk, to be backported in the future to 12.x) does have a screen where this feature is explained a bit more, since there was a change in the way tiki handles that behavior before Tiki 12 and in Tiki 12+