AskMecha: Meeting with the boss' boss tomorrow...to talk about the boss. Advice? →[More:]

Here's the situation:

My boss is disorganized, and despite his good intentions, there are tangibly negative effects that take place because of this.

The boss' boss has expressed gratitude for me being in my position as a senior person who often has time to help the boss, and wants to know "how I'm getting on". I'm a bit frazzled, really, and I'm struggling to keep other responsibilities from slipping. I've been frank about this with the boss, and he sounds sympathetic but doesn't let up the pace of his needs.

The most irritating thing, though, is that I'm not getting paid for my time giving extra help to the boss, and to make matters just that more knife-twisty, the boss has a new assistant boss who's still learning the ropes, but who should really be the person jumping in and helping out when they can.

I'm happy to help when I can; I have some management responsibilities as it is and I can handle those well - I've done so for a few years now. But I can't train my boss and his assistant boss *and* maintain the quality of my work. It seems like I'm being set up to fail, and I can't stand that.

The actual question:

How do I frame this situation to my advantage? Boss' boss is a kind man - but only understands the big picture of what we do on a nitty-gritty level, so I don't want to overwhelm them with details of complaints about my boss himself.

Ideally, I'd like to negotiate either more clearly defined responsibilities and expectations, or higher compensation and recognition for what I do. I'd love some ideas on how to phrase this.

Complication:

I can't walk - the company sponsors me on a work visa where I'm living; if I go, so goes the visa and I'd have to move home where there are no jobs in this field.

Thank you, Mechazens!