It seems to happen only when I've been away for a long time. I don't think it was happening before I enabled the "check friends" option; I'm disabling it now just to make sure it's a relevant factor. My hardware is a DVI TiBook. The only aspect of my usage which I know to be unusal is that I frequently switch accounts using "Login As". I am running 1.49.
Is this a known problem. Are other users experiencing the same thing? Is there a fix or workaround?