Sorry, should have mentioned of course. The systems are Windows 7 64bit + Windows 2008 32bit. The file size is 559 KB. I just renamed the file again + inlcuded the addtional dot, but now the sync works. Thus, I can't reproduce the issue, but can tell, when it happenend, removing the dot solved it, but maybe any other change of the file name would have solved it, too.