I have made a bit of an error it seems.
Disconnected from LDAP this morning and was presented with a blank user / group list. I enabled system user names, and then set up one account as standard user using my own credentials.
I now cannot log on as administrator as of course my windows log on is associated with my single standard user in the database.
I've tried using the -u and -p switches on a shortcut but this does not work and now the admin account appears to be locked out.
On the verge of calling IBM support...