Follow-up: The problem was found to be due to the way VFP's RENAME command works with NT. I had used RENAME like a COPY command...
<*!* rename (myfrm.appdir+myfrm.userdir+lcleandbf) to (ldbfname)
>>NEW CODE copy file (myfrm.appdir+myfrm.userdir+lcleandbf) to (ldbfname)
NOTE: ldbfname was a fullpath name.
Old code had retained the myfrm.userdir folder's NT permissions, whereas the new code inherits the NT permissions of the destination folder, where the file is copied.
Bottom line: In NT, a file move retains source folder access rights. A file copy inherits destination folder access rights.
