I actually missed a step out before setting the user homes in the workgroup manager goto the server admin and select the old root home folder (in my case User_home) and deselect the Automount option then goto the new USer home and select the automount option. You will need the ldap admin username and password for this.
Ok so now I have moved my users and everything is working well I need to figure out how I actually get the network share for that user to open automatically rather than having to log in and then goto go -> connect to server-> server name, enter your password and select the share. Easy in windows, cant see how to do it on the mac just yet - most of googling the subject comes up with connecting to a windows share or some such. Other solutions suggest some applescript programming type stuff. Anyone know of any reliable way - surely this is something you should be able to set at the server level for when the user logs in - typical last hurdle is a killer.