samba doesn't writeable on ubuntu server 8.04 LTS

[phoenic]

Hi all
I met a problem on creating an writeable samba share.
here's the configuration file.

[share]
        comment = Shared folder
        path = /media/smb
        valid users = root,@somegroup
        invalid users =
        writeable = yes
        write list = root,@somegroup
        create mask = 0775
        directory mask = 0775
        allow hosts = 192.168.0.0/24

The strange problem is I can write file into this share from a windows client. But I can't write files into the share with "Konqueror" of "KDE". I have kubnutu 8.10 installed on all other clients. The best way to access the shared folder maybe type "smb://server/share" in the Konqueror. I think the problem maybe on the Linux clients, but I still doesn't get the key point.
Another problem is seems the samba service is running with root account on this version of ubuntu, is it safety on security? If not, how can I improve it?
Thanks a lot.

[phoenic]

No one knows? help please.