As of June 21, 2005 these fixes have been incorporated into the main ns source. So, ns-2.29 and later (as well as snapshots after June 21, 2005) will have these fixes.
All fixes are based on ns-2.27/ns-2.28 and only require modification to ns/tcp/tcp-full.{cc,h}.
Some of these fixes correct behavior which later expose other
problems. Any dependencies are noted in the problem description.
Patches
ns-2.27, ns-2.28: tcp-full-fixes.patch - last updated Aug 31, 2006 (fix in "got packet lacking ACK", now matches soon-to-be-released ns-2.30 implementation)