Some tips on troubleshooting Open Directory.

Toggle for debug logging in Directory Services

$ sudo killall -USR1 DirectoryService

To toggle debug on startup

$ touch /Library/Preferences/DirectoryService/.DSLogDebugAtStart
$ sudo killall -USR1 DirectoryService

To toggle API logging

$ sudo killall -USR2 DirectoryService

To check error codes

$ man dserr

To check on authentication on Directory Service, use the dirt command

$ dirt -u username -p password