sftp protocol not use ssh-agent

[Thomas]

Binary package hint: gvfs

i have the follow entry in my ssh config

Host s01.server.de
Hostname s01.server.de
IdentityFile2 /home/user/.ssh/id_dsa
Port 22
PreferredAuthentications publickey
Protocol 2
User user

so when I connect with ssh s01.server.de and my ssh key in unlocked in the agent, I get logged in, without entering a password.. everything ok..

But when I try to connect over nautilus "sftp://s01.server.de/" i get only the error message:

»sftp://s01.server.de/« konnte nicht angezeigt werden.
Der Zugriff wurde verweigert.

I try to translate in English:
»sftp://s01.server.de/« can not be shown.
Access Denied

I also not get a Password Dialog or something else...

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 8.10
NonfreeKernelModules: nvidia
Package: gvfs-backends 1.0.2-0ubuntu3
ProcEnviron:
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: gvfs
Uname: Linux 2.6.27-11-generic i686

[Thomas (t.c)]

Ok.. I made a second test:

I changed PreferredAuthentications to publickey,password and now I get asked for Password... But I want, that it use the SSH-Agent