If you get a java error '4488 Server access denied' when trying to use a context menu in "My Places" (e.g. to lock or delete a place) in Lotus Quickr (Domino Services) you should make sure that the Quickr user is allowed to access the Domino server.
In the server document in the Domino directory check the setting Security -> Access Server. This setting should either be empty or you should add the Quickr users into this field (or into a group which you can then add into this field).
The user would be able to access Lotus Quickr without being part of this group (as this is for Notes client users only) but the Java applets will have problems in this case.