Packets are dropped when setting small receive TCP socket size SO_RCVBUF=3096 in Red Hat Enterprise Linux 6.3

Issue

When setting a socket's receive buffer low to SO_RCVBUF=3096, packets are lost and buffers overflow in RHEL 6.3, though this worked fine in RHEL 6.2.

This issue only exists when RHEL 6.3 or later communicates with Solaris. RHEL 6.x RHEL 6.x seems to not exhibit the errors.