It seems that the latest Apple fix for Snow Leopard fixed the problem of the crashing Mail application. After 10.6.2 I have had no problems. I view the problem now as solved.
I am using a MacBook Pro 4,1 with 2 Intel processors. I am running OS 10.6.1. Ever since I installed Snow Leopard, my Mail app has misbehaved. It crashes routinely whenever I add an attachment. It never did this under 10.5. It also crashes occasionally when I save an attachment. Sometimes...