Please, don´t bother buying back in, cause we´ll never get rid of you then  

@ nzminer: Alice is just the name of some pretty consistant nodes, but i go to nodeexplorer and try all the nodes, which are on the latest version, 0.6.31, because older ones will kick you out (without you noticing, when you closed the client), when they update, anyway.

And no, you don´t have to wait. When you put in a new IP of a node in "settings", you go to the "Start delegated harvesting" button immediately . Try to start that, and if no work (Oops, bla bla . .), insert next IP immediately, try again, until you get the button to show:"Stop delegated harvesting".
Many nodes are fully occupied, so just try until you get no more "Oopses"  

The waiting thing and 6 XEM-fee applies only to the initial "activate (generally) delegated harvesting", on the top right, ONCE only.