Allow filing a contribution/participant/membership directly to a case

Looking at the ability to file a contribution to a case I can see two issues. Not sure if they are both specific to 4.5 beta. One is a functionality issue (it doesn't work) and the second is a UX issue (this is not what the user would expect to have to do).
1. When viewing a list of activities from the "Find Activities" menu option (http://drupal.sandbox.civicrm.org/civicrm/activity/search?reset=1) I can see contribution activities and can successfully file such an activity to a case using the available command.
However if I view the Activities for a given contact by selecting the Activities tab from the contact summary screen, and - using the exact same method - try to file an activity on a case, nothing happens.
I've just done all this on the live 4.5beta5 demo site.

2. The UX issue: if I am attempting to file a contribution to a case I would naturally look for the contribution, and expect to be able to file that contribution to the case. The fact that I need to find not the contribution but the contribution activity, is counter-intuitive. From an ease of use perspective users should be able to file the contribution to the case even though it is in fact the contribution activity that is being linked.