Mavericks 10.9.1 - Copies fail *after* the data has been actually moved
Mavericks uses SMB2 as default, which still is a little bit buggy and might be causing this problem. You can force Mavericks to use SMB again by entering this in Terminal:

echo "[default]" &gt;&gt; ~/Library/Preferences/nsmb.conf; echo "smb_neg=smb1_only" &gt;&gt; ~/Library/Preferences/nsmb.conf


and restore SMB2 default by:

rm ~/Library/Preferences/nsmb.conf


Source: http://hints.macworld.com/article.php?story=20131122083837447