Weird permission problem

[Jan Danielsson <jan.m.danielsson%gmail.com@localhost>]

Hello,

   One of our systems started exhibiting an odd behavior recently.  All
Of A Sudden(tm) (no changes to the system), programs in /usr/pkg could
no longer be run; whenever I try to run anything I get a permission
error.  Here's what's really strange, at least to me:  It's not a
separate mount (it resides in the same mount as /).  Listing the files
obviously shows that the execute permissions are set as they should, and
there isn't a user/group problem (just to be clear, it worked one
minute, the next it didn't).

   I'm not entirely sure that the issue only affects /usr/pkg (or the
entire /usr/pkg), but the rest of the system seems to be ~fine.  The
problem is persistent across boots.

   One of the temperature sensors seems to have gone fubar, so we're
going to replace the system -- once I get the system brought here I'll
be able to look into it more closely.  Until then, anyone have a clue as
to what may have happened?  Any non-destructive things I should try?  (I
don't want to run fsck until I have the system here and can make a few
final backups).

   Running NetBSD/amd64 -6 branch since a few weeks back.

-- 
Kind Regards,
Jan