Unless I've missed it somewhere in your posts, you haven't said anywhere why you think this is linked to the bug in this report. You said you're not using any background images, so are you using picwins? If not, it's very possible it's unrelated to this bug. If your memory usage is the same then it almost certainly is unrelated, in which case it probably deserves its own thread.
Assuming it isn't related to the image issue all I can say is that it definitely isn't a problem for everyone. I've got a couple of very mediocre systems that show no slowdown after hours or days of running.
