It appeared that the backup2ws started working after two changes:
1. The PC name were replaced with ip number, so that the Windows machine were addessed this way: //10.0.0.123/share
2. I included the Windows administrator name and password in the windows logon field.
(Don't know if both were really neccessary, but at least it works now.)
One other thing: I made some series of experiments copying files to secondary hd and other computers. I also opened the backup files from the ordinary backupfunction and from backup2ws to see the content. As far as I can see, the bacup2ws disaster backup is identical with the ordinary backup when it comes to content. On the other hand .. just a copy of the same directories will not work as a safety recovery, as the two backup alternatives of e-smith both make database dump of all mysql tabels and some other smart things, that an ordinary copy of directories will not take care about. (Destroyed 2-3 test installations before I realized that.)
Tried to make a copy to a lacal HD using the backup2ws module. This did nor work so far. It seems like the backup2ws module (and the ordinary backup function) is using some of the functionality of the SMB/SAMBA so it will as a general prinsipple only be possible to make a backup to a Windows machine (or another Samba server ???)
If some of you have more details about how theese bacup functins work, I would be wery interested to know.