Minimizing is BAD BAD BAD BAD, mmkay? You absolutely MUST be able to see whispers on all clients. Think about this. You have CloneX, CloneY, CloneZ, and Clone0. Well, you play CloneX as your main, but the GM gets the typical "lame botter" complaint and goes "meh, probably just multiboxing, I'll ask him". So then he whispers CloneZ and goes "Hey, I got a complaint about you....you a bot?"

Then, you spend 10 straight minutes grinding in an instance. Now what's that gonna look like from their perspective? Bans I tell you, bans!!

Never minimize if you don't have to -- keep chat windows nearby.