I thought I had seen this reported before, but I'm not finding it, so
here goes ...
If an object of the same name exists in the user[1] and the public
schema, then using the delete/drop command on the object in the public
schema in pgadmin3 (1.2.0) can cause the wrong object to be dropped.
The cause seems to be not including the schema name in the drop
command when the schema is public. Since the default search path puts
the user's schema before the public one, this will drop the wrong item
in the default config. And who knows what the user might set the
default search path to in the postgresql.conf.
[1] i.e. the schema with the same name as the logged in user
-- -- Cheetah