It seems that the i_icon_id was not saved for servergroups, although they would be present in the YaTQA snapshots. I think they have to be reassigned for each group, at least you dont have to upload them again. I copied the icons after I imported the snapshot. Maybe it would work if you copy the icons first, and then import the snapshot.In your case, did all server groups have to be reconfigured for the icons manually group by group?
The icons for channels were displayed correctly without the need to reassign them.