from time to time I review some of the oldest bug reports to see if they got fixed despite not being updated or closed. So I created from scratch and saved two files with the official 2.69 release, one with a few primitive meshes grouped together, and a second .blend file from which I linked the grouped meshes in a particle system, attached to a subdivided plane, with "Counts" option enabled. I then noticed the following:
A quick update on this issue. Tested with the current release candidate 1 of Blender 2.7.0 (hash 19f7f9a) and I can confirm that the use count still works fine when directly linking a group of objects for another file (first level linking) but it doesn't with a second level or multiple level linking as per example file link_par_group.zip.
To be correct, it works at first when you add the linked group reef_final from file reef.blend into a third file (multiple level linking), but the use count is then lost at the next opening of this third file.
About the firstframe_bug. zip example I confirm that the second/multi-level linking works after running first the linked in script and then updating the frame number, at this point the correct use_count is recalculated correctly. Sort of workaround and perhaps a clue on where further investigations can be done.
Hope it's clear enough and thank you for looking into this matter.
Yes, no point in trying to fix this i guess.