The Ids used by trash slave is fragile (David's words) and integration with mediamanager sounds like a good idea (as of 30.10.2006 :) And the real practical problem is that to recalc the ID, trash:/ has to scan all parititons. So all your hard drives have to wake up so you can trash something on one of them. Which is a bad limitation.
Dupe of http://bugs.kde.org/show_bug.cgi?id=95654 :)
*** This bug has been marked as a duplicate of 95654 ***