Ron-

Sorry I haven't responded in a while. So you had the standard version of OmniOutliner. That explains this whole mess actually. I assumed you had the professional version (doh!) since you made your own template.

So, the standard version does not support making custom templates. This also means it won't check for any custom templates. You can however use custom templates by double clicking the file like you were.

Sorry for the confusion!

--
Derek M.
Support Ninja
The Omni Group

Actually...
 

Actually Ron, there is a way to save your custom template in OO3 (non-professional). Create the template as you need it and click "File>Save As..." Next save the file to your desktop as something professional (I used "Research Paper.oo3template" for example). Make sure you select "OmniOutliner 3 Template" from the "File Format" drop down.

Now you need to find the OO application in your applications folder. Control+click on it and click on "Show Package Contents." Now follow this file tree: "Contents>Resources>English.lproj>Templates." All you have to do is drag and drop your template from your desktop to this folder and relaunch OO3. From now on, when you go to "File>New From Template" your custom made template will be right there amongst the rest of them!

Hope this helps!