In the initFindAdvanced method of the Find.java class (package org.compiere.apps.search) the dislay type for button fields is changed to table or list => a wrong editor is created for this fields. For example the posted/DocAction fields is displayed as a combobox (list) in the GridWindow and not as buttons.
This happens only if the table (ex. Order) of the window is marked as high volume and you switch to the advanced tab of the find window before the main window (ex. Sales Orders) is diplayed.
PS: I attached the Find.java class fixed by me (search for comments: // bit / mk - fix for button display type).