Multiple key problem with exmh?

[Dr. Lyman Hazelton]

I am running GnuPG 1.0.1-2 under Red Hat 6.2 and trying to use it with exmh.  
I successfully (well, it *looked* successful, anyway) imported the keys, 
public and private, from my previous PGP 5.0 keyrings.   I have three secret 
keys on the secret keyring.   I can successfully, it appears, sign and encrypt 
a message and send it to myself as a test with exmh.  Prior to sending it, I 
can choose which key is to be used to encrypt and sign the message.  I chose 
the newest (just created with gpg).  When the message arrives it is properly 
marked as encrypted, but when I try to decrypt it, it asks for the passphrase 
for the wrong key.  I must be missing something fundamental.   Anyone have any 
suggestions?

Thanks, in advance, for your time and assistance.

       -Lyman