I see a similar symptom, but I only see it when receiving large files. Sending large files works flawlessly at around 10MB/s, as does receiving files at around 1.2MB/s. I can replicate with 100% reliability when copying a file to the affected machine via the local network.
** Attachment added: "output of lspci -vv" http://launchpadlibrarian.net/20968116/lspci.out -- Unreliable network connection with B44 driver https://bugs.launchpad.net/bugs/279102 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs