I am not sure whether this is related to the problem discussed on the mailing list in May (see the thread containing http://www.haskell.org/pipermail/haskell-cafe/2012-May/101491.html)where I failed to reproduce the problem on a variety GHC compilers including GHC-7.4.1 running on CentOS 6. This should have been an exact match for one of the configurations for which the problematic behaviour was being observed. I don't remember seeing any explanation for these differences in behaviour. (I use the LDAP quite heavily on CentOS 5 and CentOS 6 and have never seen any of these described problems.)
This is the test program I was using. It gets all the details of the LDAP server from the user so the exact same code can be used to test different installations.
import LDAP
main :: IO () main =
do putStrLn "domain>"
domain <- getLine putStrLn "bindDN>" bindDN <- getLine putStrLn "bindPW>" bindPW <- getLine putStrLn "conecting..." ldap <- ldapInit domain ldapPort ldapSimpleBind ldap bindDN bindPW putStrLn "done"
Of course it uses the LDAP package.