tail command errors on windows/dos log file

When tailing a log file created within Windows, I receive the following error when I issue:

tail -f mylogfile.log

tail: mylogfile.log: cannot follow end of this type of file; giving up on this name
tail: no files remaining
/mnt/test > 

Any ideas why a DOS file cannot be followed using tail from CYGWIN but a winnt tail command works?
Chris