Cannot connect to time machine folder, using mac


I have a WD My Book World Edition II 2TB and I have set it up to use it with a Macbook having the latest version of Snow Leopard.

I followed all the instructions and the time machine is running OK. However on the manual it refers to an option for being able to delete the full time machine backups. Normally you get a connection failed but if you try connect as and give the time machine credentials you can see the sparsebundle. I have tried this but when I press the connect as button nothing happens so, I cannot see the folders described in the manual. The reason I want to connect is to try transferring my old time machine backups on the NAS from a WD Passport external disk. I also want to have the option of deleting the complete time machine file and start over on the future (maybe if I get a new mac…).

Can anyone help on why I cannot “connect as”?

thank you