workgroup settings wont 'stick' in 10.5.8

OK, I've had this mac for years, but never been able to network it on the workgroup.....

I need to alter the workgroup name to 'workgroup' (as it currently isn't assigned a workgroup name), however, when I try and change the workgroup name, I click apply and the settings just get reset to default.

ok, I do some googling, turns out its a known bug, solution suggests create a new 'location' by duplicating the 'automatic' location, and making changes there before switching it out and deleting the original, so I do that, but after creating the new location (even before making any changes) I cant get it to switch to the newly created location, but it stays connected to the wifi network using the 'automatic' location.

If I turn off airport (as far as I understand airport is mac speak for wifi network adapter?) the network goes out (as expected) but as soon as I re-connect airport, the newly created location dissapears and is deleted....
If I delete the original 'automatic' location before reconnecting airport it dissapears, but as soon as I recconnect airport, it comes back and deletes any new locations I've created...

This cant be right... right???

Its not locked, I've tried locking and unlocking the padlock, Im logged in as administrator, I have read and wright access for my login name (the only login), "staff" and "everyone" on the HD and those settings have been shared with the subfolders..... this mac is a good 5/6yrs old, but its probably done less than a days work because I've never been able to get this working (still got plastic on the screen and all!), I've genuinley spent more time trying to figure this problem out then the thing has even been used for, and every time I give up due to lack of success.

HELP! :/