[Radiant] Comments extension error

[Mailing]

When I try and run rake production db:migrate after installing the 
comments extension (by Art of mission) I recieve the following error, 
any ideas?

wedemo3 at wedemoweb3.co.uk [~/radapp]# rake production db:migrate:extensions
(in /home/wedemo3/radapp)
rake aborted!
undefined method `page_edit_parts' for #<Radiant::AdminUI:0xb7a40ba8>

(See full trace by running task with --trace)