"No MTP devices." and "No devices." folders persist, others invisible to exmh

Hi folks,

I woke this morning to exmh having only two folders, "No MTP devices."
and "No devices.". This is the content of ~/Mail/.folders so I 
removed that file and exmh reset the contents to the same again.

nmh finds my folders just fine.  The two odd folders are not reported
by 'folders' of nmh.

What's going on?  I haven't changed exmh nor updated my system in a
long time, let alone while I was sleeping.

Thanks all....

--
Kevin