New Agent Queries/Old Agent Quandries

I signed with an agent almost two years ago to help me sell a YA manuscript. That partnership ended unsuccessfully last January.

She had gotten four invites from publishers, but (in my opinion) got bored with the project and quit working about six months before the partnership ended. Two of the invites weren't even followed up with until the week before we split. Grrr.

Anyway, I have revised the manuscript, and I'm ready to start shopping it around. This time, I'm looking for an agent with a little more experience in the YA market. I think I've learned that much, at least.

My question is: at what point should I mention to the prospective agents that this project has already been agented? Should I mention it in the query? Follow-up? Should I mention the publishing houses that invited/rejected the manuscript already? How far back should I go?

giftedrhonda, that's what I was thinking. I'll get the agents' attention with the MS, then sort out where to begin afterwards.

rwam mentions the title, which isn't really an attention grabber. So far, I've tried The Sandal on the Obelisk and Hawk, Sandal, Obelisk. The story is based on an Egyptian Cinderella-style story: a hawk carries away a girl's sandal and drops it at the feet of the crown prince. It ends with the characters reading their own story in hieroglyphs on one of the obelisks of Memphis.

I'm thinking of just creating several book covers and trying out the titles on friends and students. Any other useful ideas for generating titles?