The problem
Subversion doesn’t know something about network filesystems like samba or nfs. So kdesvn (and any other client) isn’t able open repositories or working copies starting with smb:// or similiar. (Within Microsoft Windows it may possible ’cause there in system below subversion the samba filesystem is integrated. But I don’t know ’cause missing windows)
Same for other network filesystem like nfs or afs.
So for accessing any not local filesystems within linux or unix the remote filesystem must mounted into local structure.
Solution for samba
The best way integrating smb-filesystem into local filesystem from my point of view would be the fuse-smb package. When using it you don’t require root privileges mounting the remote filesystem and you may mount it when needed into your HOME-folder. Than you may access repositories or working copies inside this samba shares.
Solution for nfs
Depends on your requirements. I would prefer the autofs system. You only have to activate the entry with /net at beginning of line in /etc/auto.master and check the options in /etc/auto.net.
Of course you may setup nfs mounts inside /etc/fstab.
Troubles
Accessing repositories via networked file sytems isn’t a very good idea in most cases. Sometimes you may get problems with access rights or locks and so on. NFS may be ok, but samba I would not trust, it is simply not designed for that.
Better way would using subversions built in server on repository so you may access it with svn:// (or ksvn:// with kdesvn). This service should work on windows machines, too as far as I know.
Hope this helps, I’m not the expert on samba and/or nfs, but always saw problems with samba and subversion not depending on the system. If someone has better ideas please tell me.