21.4.3 copy-file

Under 21.4.3 on windows (& cygwin), when I try to save my vm inbox I have been getting: Cannot write backup file; backing up in ~/%backup%~ This did not happen under 21.1.13. I tracked this down to backup-buffer in files.el that does: (copy-file real-file-name backupname t t) Under 21.4.3, when I do (copy-file "c:/home/jmincy/INBOX" "c:/home/jmincy/INBOX.~3333~" t t) I get I/O error: No such file or directory, c:/home/jmincy/INBOX.~3333~ Under 21.1.13, the same copy file works without I/O error. -jeff