I have setup an AAA connection from my ASA5505 to my MS-AD domain controller for VPNs (SSL and client). It was working, however, last week the connection between the two failed and I cannot get it back up again.
I've checked password, usernames, object locations etc. but to no avail. When I do an auth test, this is the debug ldap 225 output:
 Session Start
 New request Session, context 0xd4e225c8, reqType = 1
 Fiber started
 Creating LDAP context with uri=ldap://w.x.y.z:389
 Connect to LDAP server: ldap://w.x.y.z:389, status = Successful
 supportedLDAPVersion: value = 3
 supportedLDAPVersion: value = 2
 Binding as administrator
 Performing Simple authentication for FirewallTest to w.x.y.z
 Simple authentication for FirewallTest returned code (49) Invalid credentials
 Failed to bind as administrator returned code (-1) Can't contact LDAP server
 Fiber exit Tx=253 bytes Rx=583 bytes, status=-2
 Session End
I have tried the age-old "remove and re-add" fix, but this has not worked.
Have you checked the the user account used for binding to the LDAP server (AD) has not change it's privileges, I remember that after applying a patch to an AD server most of the Admin accounts were changed to local admin rather than domain admin accounts.
Also, try reseting the password for this account and see if you have the login-dn correct, get the "dsquery user -name " and compare it to your ASA.