We had the same problem with two java script widgets having a cyclic relationship.
So I wrote the following select query to find all the cyclic objects. In our case it found 3 couplings although we had only one of them causing the crash.
Wing1.ID, Wing1.sibling_id, Wing1.object_type, Wing1.page_id, Wing1.parent_prop_id, sf_object_data.id,sf_object_data.sibling_id from sf_object_data as Wing1 inner join sf_object_data on Wing1.id = sf_object_data.sibling_id and sf_object_data.id = Wing1.sibling_id
The following update query will break all the cyclic relationships
from sf_object_data as Wing1 inner join sf_object_data on Wing1.id = sf_object_data.sibling_id and sf_object_data.id = Wing1.sibling_id
For none SQL Buffs the joining on the two fields of id and sibling_id for both the alias table and the sf_object_table restrict the result set to only the cyclic objects. Note that each pair will appear twice in the result set.
I hope this makes it easier for anyone else with this problem