Did you also try this after cleaning up the "same as parent folder" records?
ldap://intra.s4isystems.com/dc=intra,dc=s4isystems,dc=com
You may also consider simply creating a host (A) record in DNS called "ldap" and pointing it to the IP of your Domain Controller. That way you can use:
ldap://ldap.intra.s4isystems.com/dc=intra,dc=s4isystems,dc=com
Note that the "ldap" name for the record is entirely arbitrary, it doesn't mean anything, just an easy way to keep track of what it's for. If you only use the application for your domain this is a reasonable approach, dynamic discovery is only useful to learn if you need to be selling the code :)
Chris