When trying to import(update animation) a locator with custom attributes, only translate,rotate and scale values are updated, any custom attributes wont update.

To avoid any unsimilarities between the locators, I also tried this:
If you begin with an empty scene and first do an add import, It will show up as a group.
Then if you try to break connections, zero all attributes and then do the update animation import, those values still wont update.

Hello Tistatos!

I think the first test you could run is to update your version of the FBX plug-in (2012.2).  I’ve gone through your steps and did not run into any problems updating my locator’s animation, even the custom atttibutes.

Now, this was all done with the 2012.2 version of the plug-in on Maya 2010.

So, I would say update your plug-in first, and then see if you still have the problem, please let us know and we’ll see what we can do to help.

You can find it here: http://usa.autodesk.com/adsk/servlet/pc/item?siteID=123112&id=10775855

Cheers!
Carlos