bboston,
Just came across your thread. I also have a Jamis Nova 47cm with a 26" front and 700c rear wheels that I also got on eBay a few years ago. It's lime green and year 2000. I love it and have mainly used it as an all-around bike. The smaller front wheel is to deal with toe overlap, I believe. I've had no problems and like the feel of more control. Carrying 2 tubes can be a pain, though. One advantage is the range of tire sizes available. If you're looking for a cross tire, try the Schwalbe CX Pro 1.3".

Have you tried any 'cross races on it? I'm looking to try it this fall and wonder how it works. Going to an intro CX clinic this weekend ...