How did you go about re-adding the foreign key constraints after you re-created the table? It seems likely that you have data in other tables that reference ec_user_classes, and the foreign key constraints are kicking in, but not giving an error message. If this is the case, you are seeing normal operation of except for the lack of an error message. To see how to add the foreign key constraints, go through your dump file and search for "create constraint trigger" statements which reference "ec_user_classes". It would be nice to be able to isolate this down to a specific constraint trigger. You could also try initiating the deletion from a .tcl script. I think I now remeber coming across this before, where deleting from psql would only give DELETE 0, but doing the same deletion from a .tcl script would come back with a referential integrity violation error message.
