Trying to add a logical network to an interface fails with `Network is currently being used (Error code:28)` on RHEVM.

Issue

While trying to add an interface from Hosts -> Network interfaces to a logical network, it fails with the below error message.

Network is currently being used
(Error code: 28)

/var/log/rhevm/rhevm.log has the below error message at the same time.

2012-03-05 07:57:41,919 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.BrokerCommandBase] (http-0.0.0.0-8443-5) Failed in AddNetworkVDS method
2012-03-05 07:57:41,919 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.BrokerCommandBase] (http-0.0.0.0-8443-5) Error code ERR_USED_BRIDGE and error message VDSGenericException: VDSErrorException: Failed to AddNetworkVDS, error = Bridge already exists
2012-03-05 07:57:41,920 INFO  [org.ovirt.engine.core.vdsbroker.vdsbroker.BrokerCommandBase] (http-0.0.0.0-8443-5) Command org.ovirt.engine.core.vdsbroker.vdsbroker.AddNetworkVDSCommand return value
 Class Name: org.ovirt.engine.core.vdsbroker.vdsbroker.StatusOnlyReturnForXmlRpc
mStatus                       Class Name: org.ovirt.engine.core.vdsbroker.vdsbroker.StatusForXmlRpc
mCode                         28
mMessage                      Bridge already exists