[Evolution] GUI question: clearing Inbox messages

[jim <jim well com>]

   A couple of times I've had the troubling experience 
that while mousing about the mail GUI, much or all of 
the contents of the Inbox (current folder) inadvertently 
disappears. I certainly did not deliberately highlight 
and delete, and seems unlikely to have done so without 
knowing. 
   I've used the command line to investigate: no clue. 
It seems messages have been erased, not moved. Note that 
not all messages are affected. 
   Can't find clues in Evolution Help. 
   What mouse or mouse-keyboard events select and clear 
contents of mail folders? 
Hopefully, with thanks, 
jim