Smarty editor not properly associating with *.tpl files

[tiptone]

Installed the Smarty Feature in Zend Studio 12.5 on several machines (Macs). On one machine the file association is correct but on the others the Preferences show that *.template and *.tpl files are associated with the Smarty Editor but double-clicking a *.tpl file opens an external program. Right-click -> Open With -> Smarty Editor works as expected but is a laborious way to open every *.tpl file.

[ajmaske]

Just installed pdt on neon, association appears correct, that is clicking to open a .tpl opened it correctly, however the tab/shift tab does nothing. tried manually adding the key/command but still not working. In short, Tab/Shift Tab is not working in .tpl/.template files.

Was finally able to get the keys working by adding both *.tpl and *.template to the Content Type under "PHP Content Type".

[EmilObermayr]

Here are some .tpl files correctly associated to the Smarty-editor. Others are not. This is a fresh installation over an existing GIT-project. The content-type and the file-ending are both correctly set. In the preferences the Smarty is the top-most choice and open-with works.
So: Where are the assocciations for individual files stored/cached and who that can be deleted or flushed? I searched properties and other file information and did not find anything.
Any hints?