Steve,
Make sure that the dsaUser and dsaCredentials are correct including case.
I've also seen it require all caps. Also, you might want to experiment
with different ways to identify the dsaUser.
Full path to user
Email address
sAMAccountName
You can try to connect via the Syntegra LDAP Browser first to find out what
works - this is easier to try different permutations a lot quicker than
changing the jndi adapter and cycling the MS.