Hi,
I Just experienced a similar problem when migrating from angua to ponder stibbons, and the next day to Hrun.
In both cases we experienced the same problem.
We use authldap. Some users could not login, some other could. LDAP debug indicated this :
LDAP user search: Success [auth.php:188]
LDAP search at: ou=People, dc=mydomain, dc=com (&(uid=user)(objectClass=posixAccount)) [auth.php:189]
LDAP group search: Success [auth.php:233]
LDAP search at: ou=Group, dc=mydomain, dc=com (&(objectClass=posixGroup)(|(gidNumber=987)(memberUID=user))) [auth.php:234]
LDAP usergroup: IRE3 [auth.php:253]
...
LDAP usergroup: I [auth.php:253]
LDAP: bind with uid=user,ou=people,dc=mydomain,dc=com failed [auth.php:115]
LDAP user bind: Invalid credentials [auth.php:116]
The password that the user typed in was correct. Clearing the caches (doku and browser) had absolutely no effect.
Surprisingly, connecting with another browser solved the problem.
After deleting all the cookies related to my site on the first browser, users could log in.
/Schplurtz.