Cifs "mount error 13 = Permission denied"

most of ppl forget to put domainname before username ...
wrong one is
 mount -t cifs //Machinename/folderonwindows /mnt/folderonlinux/ -o username=username,password=password

correct one is
 mount -t cifs //Machinename/folderonwindows /mnt/folderonlinux/ -o username=domainname/username,password=password

and using direct ip instead of Machinename can cause trouble....