> I have a number of files (videos and pictures) on my hard
> drive that are being re-downloaded due to the time stamp
> even though they have not changed (I uploaded the files to
> the server and Frontpage changes the file time).  HTTrack
> thinks each file has changed and therefore tries to 
download
> it again.
> Is there a way to force HTTrack to keep the existing .mpg,
> .jpg, .mp3, .wav files even when the time of the file has
> changed ?
The short answer: No.

The long answer: The update process is only using the 
server's heuristics to detect if a file was modified or 
not. If the server was smart, I suppose it could hash the 
file, and use this hash as an etag-cookie to prevent this 
problem from happening. But most servers (all ?) only use 
the date for files, and this is bad.

By the way, your ftp-client (or maybe the remote server) is 
probably also not very smart: most "modern" ftp transfer 
clients/servers are able to set the remote date to avoid 
this kind of problems.