I had this trouble too, so I did a number of different things to learn to hear the beat:
1. Got dance music at a half-priced bookstore & listened to it in my car. Tapped out what I thought of as the beat on my steering wheel.
2. Danced with women at parties, and followed their beat. If you pay attention, you can learn to pick up their beat by looking at how their body moves without actually dropping your head to look at their feet (although i did a lot of this at first)
3. I took private lessons. This was pricey -- ouch -- put I don't regret it. Still taking group lessons.
2) was probably the most helpful. But they all helped.

It all gets better with practice...

Jim,

Thanks for good suggestions. I hadn't thought of some of the things you recommend. But, at this point for me, I really need to work in a very methodical way with a musician with strong understanding of Salsa music and dancing.

This is a great post Doug - you have peaked my curiosity as a salsa instructor. I have posted your dilemma on my own blog that is viewed by students.

http://www.torontodancesalsa.ca/blog/2007/11/musicality-insteresting-find.html

I can't wait to check out your progression - good luck!

It takes special skill to teach people to really hear and feel the clave. I can't explain it-- I just hear it. I hope Don's approach works for you.
Let me know when you are ready to get back out on the salsa dance floor!