Looks like the bug is in the driver itself. http://www.pharscape.org/component/option,com_forum/Itemid,68/page,viewtopic/t,87/sid,c91a255ab908630303a66e546a54c0bc/ ** Changed in: linux-source-2.6.15 (Ubuntu) Status: Unconfirmed => Rejected -- tty_buffer_request_room missing https://launchpad.net/bugs/58310