I noticed in the last reply to this bug that the MegaRAID Storage Manager is suspect. I'm running Ubuntu with a 3.5.0-32 kernel and see this same behavior when using the MegaCli64 command line tool. I run this tool through cron each hour to grab the logs from the RAID controller and put them into syslog. Everything was fine for a day or so and then now everytime I run the tool I an error message about the SGL buffer.
I believe this appeared in the latest kernel update for Ubuntu. Perhaps a simliar patch was applied to both Debian and Ubuntu recently? -- http://mtu.net/~jpschewe