Adding template hooks to existing profile tabs
 

This might sounds like a silly question but why when I call just created new template hook in a user profile tab template for example "memberinfo_block_contactinfo" the template hook doesn't display anything from the other hand there is no problem with it when I add it to for example "MEMBERINFO" it does display the data.

To be more strict the hook should display custom profile fields category with it's fields.
I need it to do it this way to preserve fields privacy. Otherwise I could add these fields manually without template hook involved. Or maybe there is another way to preserve fields category privacy options? Normally the category fields with privacy options display in "about me" tab but I would like to move one category fields to another tab preserving user profile privacy options Of course I could create septate tab with only that specific category fields easily using a hook in "MEMBERINFO" template but I would like to add it to existing profile tab.
Any ideas how to do this?

Why don't you post the exact plugin code and tell us the hook location so we can see what is going on.

There is no plugin for that, I've simply added a new template hook to profilefield.php in addmin panel

Then I used it in the end of "memberinfo_block_contactinfo" adding
And it works I mean it works if I use it in "MEMBERINFO" template, but it doesn't work when I use it in "memberinfo_block_contactinfo".
I must be missing something obvious here. :)

Or maybe there is an other way to add specific fields category with it's fields to that tab? Note that I need to add category, not fields themself.