Multi-site file synchronization headache

My scenario: I have folders that I update frequently, but I have
company desktop, home desktop, and a notebook used outdoors. I am
currently testing a peer-to-peer file synchronization program called
second copy 2000 (from Centered System), it works fine locally, its
folder / file synchronization, with / without deletion, with / without
backup is very good. However, since I have at least three sites, so I
take a server-based approach. I setup an FTP server, and I synchronize
folder / file between the computer I use and the FTP server. In this
case, second copy 2000 has to work together with WebDrive, which maps
FTP folder as a local drive.

Unfortunately, WebDrive is not stable in this situation, the following
problems are haunting:
1.At times WebDrive's list of folders and files are not updated or
empty, in extreme cases the whole W: drive it maps is empty. I don't
know its WebDrive's problem or FTP server's.
2.At times write failure happens in the middle of synchronization, I
can see that WebDrive's way of copying is break files into pieces. When
the error happens, the only way is to disconnect and re-connect
WebDrive, and then re-synchronize.
3.At times Second Copy will re-copy all files in the folder, even if I
didn't make any change. I am not sure whether it's due to the timestamp
difference among FTP server and local computer.
4.Because of the instability, I cannot use the "with deletion" option,
because in case FTP server folder is empty, this option will delete all
files in my local folder.

Therefore, I really need a secure, efficient and safe way of file
synchronization. Any comments are highly appreciated.

My ennvironments are:
FTP server: Windows 2000 Pro + Cerburus FTP server
File synchronizer: Second Copy 2000
FTP folder mapping: WebDrive
Home desktop: Windows XP Pro
Notebook: Windows XP Pro
Company desktop: Windows 2000 Pro
If more information is needed, pls specify, tks.

I have already lost confidence in FTP-type solution, because I have
tried:
Cerburus FTP server + WebDrive 6 + Second Copy 2000
Cerburus FTP server + WebDrive 7 + Second Copy 2000
The problem is still very big, I can't succeed copying of 30M folder /
files.
IIS WEBDAV + WebDrive 6 + Second Copy 2000
It looks much better right now.
By the way, I also fixed a time error on the server, the time-zone
should be GMT+0800, but it was set to GMT-1600, 16 hours difference!!
To make sure the time among the four sites are synchronized, I
installed NTP client service on Windows 2000 server, and enable the
time synch of XP's. Time synch is important when Second Copy 2000 is
synchronizing folder / files.