I must say that I am digging Leopard. When my laptop died, and I decided to take the plunge and go Mac, I was actually disappointed. I didn't like the the way type displayed, and I had a time getting used to the UI, coming from Windows. BUT (and there's always a but...) the more I learned and acclimated to Leopard, the bigger a fan I became. When my desktop Windows system RAID array blew up, I decided that it was time for that system to go too! Four thousand some odd dollars later, and the hook is set so deep, I'll never get it out; in fact I'm looking forward to the day when my kids' Dell dies so that I can replace that one with a Mac too.
Anyway, back to the problem at hand, the clicking on the line between cells seems to be a real aberration. When I do that, it just allows me to move the whole grid up and down with a "hand" cursor. When you say that you can't use the Library any more, what exactly do you mean? Also, when you say that all new images coming from PS end up "at the end" of the folder, what do you mean? And what file types are they? Are you re-importing TIFF's ?