Mac version (MX 2004) uploads strange files during sync

Perhaps this has been fixed in 8, but I work on a web team with 2 other people
who use windows machines. When I upload a site, it will add files that I assume
are hidden. The files have the same name as files that I've edited, but begin
with "._" (without quotes).

Has anyone else experienced this? I assume this has something to do with the
operating system (10.3), since none of the windows machines do it.

Thanks