I just globally replaced find_all with find(:all) in all project files, and it works.
Yours may work too:
<p><label for="ticket[priority_id]">Priority</label><br/> <%= select('ticket','priority_id',Priority.find(:all).collect {|p| [ p.priority, p.id ] }, { :prompt => "- Select -" }, { :style => "width: 150px" }) %></p>
Your sincerely, Damian/Three-eyed Fish