It looks like (bearing in mind this is somewhat intermittent) that this problem does not exist in the upstream kernel:
Linux joy 3.3.0-030300rc7-generic #201203101735 SMP Sat Mar 10 22:36:28 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
(at least, I have downloaded a few hundred MB at 1.5MB/s over wireless with no problems yet.)
It looks like (bearing in mind this is somewhat intermittent) that this problem does not exist in the upstream kernel:
Linux joy 3.3.0-030300rc7 -generic #201203101735 SMP Sat Mar 10 22:36:28 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
(at least, I have downloaded a few hundred MB at 1.5MB/s over wireless with no problems yet.)