Why Red Hat Satellite registeration fails with - IntegrityError: new row for relation "rhnpackageevr" violates check constraint "vn_rhnpackageevr_release"

Issue

• Red Hat Satellite registration fails with the below error:

 [error] Exception Handler Information
 [error] Traceback (most recent call last):
 [error]   File "/usr/lib/python2.6/site-packages/spacewalk/server/apacheRequest.py", line 122, in call_function
 [error]     response = func(*params)
 [error]   File "/usr/share/rhn/server/handlers/xmlrpc/registration.py", line 857, in add_packages
 [error]     server.save_packages()
 [error]   File "/usr/lib/python2.6/site-packages/spacewalk/server/rhnServer/server_wrapper.py", line 75, in save_packages
 [error]     ret = self.save_packages_byid(self.server["id"], schedule=schedule)
 [error]   File "/usr/lib/python2.6/site-packages/spacewalk/server/rhnServer/server_packages.py", line 228, in save_packages_byid
 [error]     h.execute_bulk(package_data)
 [error]   File "/usr/lib/python2.6/site-packages/spacewalk/server/rhnSQL/sql_base.py", line 181, in execute_bulk
 [error]     ret = ret + self.executemany(**subdict)
 [error]   File "/usr/lib/python2.6/site-packages/spacewalk/server/rhnSQL/sql_base.py", line 156, in executemany
 [error]     return self._execute_wrapper(self._executemany, *p, **kw)
 [error]   File "/usr/lib/python2.6/site-packages/spacewalk/server/rhnSQL/driver_postgresql.py", line 286, in _execute_wrapper
 [error]     retval = function(*p, **kw)
 [error]   File "/usr/lib/python2.6/site-packages/spacewalk/server/rhnSQL/driver_postgresql.py", line 328, in _executemany
 [error]     self._real_cursor.executemany(self.sql, all_kwargs)
 [error] IntegrityError: new row for relation "rhnpackageevr" violates check constraint "vn_rhnpackageevr_release"
 [error] DETAIL:  Failing row contains (17292, 0, 2.0.1, , (0,2.0.1,"")).
 [error] CONTEXT:  Error occurred on dblink connection named "at_conn": could not execute command.
 [error] SQL statement "SELECT dblink_exec('at_conn', in_sql, true)"
 [error] PL/pgSQL function pg_dblink_exec(character varying) line 8 at PERFORM
 [error] SQL statement "SELECT pg_dblink_exec(
 [error]                 'insert into rhnPackageEVR(id, epoch, version, release, evr) values (' ||
 [error]                 evr_id || ', ' || e_text || ', ' || v_text || ', ' || r_text
 [error] \t\t|| ', evr_t(' || e_text || ', ' || v_text || ', ' || r_text || '))'
 [error]             )"
 [error] PL/pgSQL function lookup_evr(character varying,character varying,character varying) line 19 at PERFORM