I like to have Lodestone and Lodestone forums open in the background while I play, so if I want/need to look something up I can. When I want to switch over I just hit Alt + Tab - however sometimes when I click back onto the client I get a black box with a Windows dialog telling me "Program is not repsonding".

This happens at least once a day.

Although sometimes the game will minimise itself (I've also had this happen while playing Sims 3) and go to desktop. I usually just click back into the client and it will sometimes "not repsond"

Either way I have to force close and restart the client...