I'am getting strange errors with combination mentioned in title. There is a view which creates and pushes onto control's stack a compound control. Compound control contains CAknDoubleStyleListBox and CAknSearchField. Due to great number of items managed by model I have to fill CTextListBoxModel using some kind of CActive. Since CAknWaitNoteWrapper wraps CActive, is seems to be very good solution. User is informed about long lasting process and able to interrupt filling CTextListBoxModel from DBMS. Everything is ok until user tries to switch between list and detail view (invoke form allowing to edit selected item's details). Form is waiting using built-in CActive. After returning from form's OkToExitL model is filled again with items from DBMS. Now problem occurs. CAknWaitNoteWrapper's ExecuteL panics with E32USER-CBase 21 without even entering MAknBackgroundProcess's StepL, IsProcessDone or DialogDismissedL. After checking cleanup stack's possible content I'am stuck with this problem. Any suggestions?