the problem may be very common.
When I transfer files to my FTP server all the files are transferred instead only the changed ones: For example one file on my disk has 7556 bytes and on ftp server it is 7305 bytes (same file, but different way of calculating it on both sides). So that it gets transferred even though I haven't changed there anything.
The same thing is with time difference: if I'm a few hours behind server's time my files are treated as older (assuming of course that the changes were made within those few hours) and don't get transferred.
So what I currently do is either transferring them all, or selecting them manually. But the downsides are obvious: it costs transfer limit and time and in the second case I might forget something and it also takes time.
How do you deal with it? I know there are services that host svn repos and then synchronise with ftp server. But I'm looking for a simple solution to that. I'm working on Windows XP and WAMP and using FileZilla currently. I'm looking for a free solution.