When trying to set this up on openSUSE, I ran into a few problems that differ from the description on this page, but I got it to work in the end. I'm not sure how much of this is distribution-specific and how much is due to changes in protocols and the servers.
First, it did not work to specify WURNET.NL as the server, smbclient does not report that "Homes" is an available share. Using scomp0863 as the server instead worked. I also seem to need to pass "vers=1.0" to mount options.
I also tried to get these entries accessible from Dolphin, but it turns out that /sbin/mount.cifs has to be setuid root in order to mount CIFS shares as a user, and at least on openSUSE that is not the case. (You could play with chmod to set it, but that would probably get lost after an update.) An alternative for the Homes share that does allow mounting as a user is to use Dolphin's smb: protocol. The format is "smb://user@scomp0863/Homes/user/".