I tried the Net::FTP and its mdtm method does give me the seconds. (Nice!) However, if I use this package I lose the ability to filter files according to a file pattern that you can pass into the Win32::Internet's "List" method. (Damn!)

So, one thing that might work is getting the list of files using the Win32::Internet module and then, once I have the list of files, use the Net::FTP module to log on to the FTP site (again) and check the date/time using the "mdtm" method. It's a hack but it should work.