Possibly relevant information from my now-duplicate-marked bug report:
"This bug might be related to Bug 685168, which I have been experiencing from time to time lately on this machine (as duplicate bug 692397). When I saw the Apport icon, I had assumed it was that bug again. However, in that bug, the segfault was in g_datalist_id_set_data_full() rather than g_data_set_internal() as is the case here."
Possibly relevant information from my now-duplicate- marked bug report:
"This bug might be related to Bug 685168, which I have been experiencing from time to time lately on this machine (as duplicate bug 692397). When I saw the Apport icon, I had assumed it was that bug again. However, in that bug, the segfault was in g_datalist_ id_set_ data_full( ) rather than g_data_ set_internal( ) as is the case here."