Why does the vmxnet3 driver shipped with RHEL 6 update 2 drops small UDP packets?

Issue

• After upgrading from RHEL6.1 to 6.2,loadbalancer does not work correctly.Before the upgrade only one LB was active (seen with ipvsadm -L) and used the virtual IP configured for the service. After the upgrade both LB are active (seen with ipvsadm -L) an both show the virtual IP for the configured service.
• TFTP transfer times out after upgrading the kernel to RHEL 6 update 2
• After upgrading to RHEL6.2, UDP or heartbeat packets are getting dropped when using vmxnet3 driver
• vmxnet3 update in RHEL 6.2 broke small UDP packet transmission