My WAG is that your permissions for /bin are something like the
following:
$ ls -ld /bin
drwx------ 3 Administ None 212992 Sep 5 13:07 /bin
Am I correct? If so, then when setup.exe creates a file under /bin,
Windows is causing it to inherit its parent directory's permissions.
BTW, I helped someone on pgsql-cygwin@postgresql.org with a different
symptom but the same root cause.
Jason
And again, thank you to you and all that offer help on this list. And
sorry about the off-list - didn't realize I'd done that.