CGSResolveShmemReference : offset exceeds bounds

After working on my machine for quite a bit today, I started getting crashes in certain programs, and I haven't seen this pre-10.4.4. The following was seen in Console.app:

CGSResolveShmemReference : offset exceeds bounds

And it did so for several apps, Firefox, GLterm, iSync (wouldn't even run). A simple logout and login seems to have fixed it. Nothing new as far as fixes from Software Update, so we'll just see if this keeps up, grrr.