I was thinking maybe it was related to an AFK timer, and that maybe if the client was not focused when that timer hit, the act of setting afk would cause a crash. But I have been setting in game solo (no ISBoxer) for almost 30 minutes and its been unfocused the whole time. Also I never went in AFK so, I guess that got ruled out.

I can't seem to reproduce a crash at all, without ISBoxer running the client.