This issue has been around for a while. It affects SoF+ clients (as mentioned), and as far as I can tell, it maybe limited to AMD64 platforms. Then again, I don't know which CPU architecture the other people that have this issue are using. So, I could be completely wrong about it. I've been having this particular issue since 2009:
http://www.eqemulator.org/forums/sho...d.php?p=181174
Back then I use using a single core Athlon64 w/ Ubuntu 8.04 (I only use the LTS versions). Now I'm on an Athlon II x4 w/ Ubuntu 12.04, and I still have the same problem.
I don't have any Core2 (or newer) Intel systems laying around to test with so I have no clue if the issue affects them or not.