I have the 2010 Mini (specs in sig) and occasionally get these periods of lag while typing. I'll be typing out a message, and the text is a good second or so behind what keys I'm actually hitting. It eventually appears properly but it was rather annoying, especially if you try and backspace to correct a typo. It seems to mainly happen in iChat. The problem originated in AIM, so I uninstalled it and switch to iChat thinking it was a app specific problem, but it is still happening. It will happen inside of other apps (textedit) but I mainly only notice it on iChat since I do the majority of my typing during the day on it. I've been watching activity monitor and it doesn't appear to be a resource issue (typically 60% idle on CPU, usually at least 1 gig of ram is free). I also run SMC fan control and keep temperatures at 60c on average (I typically have a game running in the back ground). I do have a Nostromo n52te hooked up via USB, it however it set to 125hz for polling, which shouldn't be a issue. Any ideas/thoughts on what is wrong? I should also add this has only happened since I updated to 10.6.4 to get the latest graphics driver update (which has been great for my FPS). But I have a hard time believe it was the update, as I would expect to see more complaints about the issue by now, shrug.