Which apps?  Probably they're just session-aware, so you shouldn't add them to autostart.

such as fusion-icon, cairo-dock, conky

i didnt use save session function. i didnt use it at all.

but i tried to save session, after i turn off all other apps except xfce4 apps, and the program do run once.

must i use save such fuction?

but still have some problem, gconf-d, xfconf, dbus-luncher, dbus-daemon run twice

i dont know if it was cause by slim, so i stop slim, and use startxfce4, it still like that.

dbus-launch/daemon cannot run twice.  It's not started by the session at all; they're started before the session.  If you have more than one running, it's because you logged out and back in and have a buggy version of dbus-launch that isn't properly killing dbus-daemon when X quits on logout.

I don't use fusion-icon, cairo-dock, or conky, so I don't know how they work with regard to session management.

gconfd shouldn't run more than once -- if it does, that's a bug in gconfd.

xfconfd cannot run more than once.  Or rather, it can, but it will quit if started more than once.  If it's starting more than once, it means you've somehow managed to launch several dbus sessions -- probably related to my point in the first paragraph.

slim shouldn't have anything to do with this.

Can you try something?  First, add the applications you want to start back to autostart (fusion-icon, conky, etc.).  Then quit xfce/X and log in to a console.  Move your ~/.cache/sessions directory out of the way (or delete it if you really don't care about your saved sessions).

Start X.  Presumably your autostart apps should start.  Log out of xfce, and DO NOT check the 'save session' box.

Log in using a console, and verify that ~/.cache/sessions/xfce4-session-$HOSTNAME$DISPLAY doesn't exist (replace HOSTNAME and DISPLAY with your hostname and the display that X runs on, usually ':0').  If it *does* exist, this is a bug with xfce4-session saving your session when it shouldn't.

Next log back into your xfce session.  Your autostart apps -- do they start only once?  Twice?  I don't see a way they could start more than once.  If they start more than once, manually inspect ~/.config/autostart and make sure there's only one .desktop file for each app you want started.

Assuming only one copy of each app started here, next quit Xfce, and DO check the 'save session' box this time.  Log into a console.  You should now have a ~/.cache/sessions/xfce4-session-$HOSTNAME$DISPLAY file.  Check it and see if any of your autostart applications are listed in this file.  If so, you should remove those from autostart and just use the saved session functionality (note that you don't need to save your session every time you log out; just do it once with your session set up how you like, and if you don't save your session again, it will stay with that setup).

really thanks very much for so kind solving this problem.

http://bugzilla.xfce.org/show_bug.cgi?id=4487  i met is because i enable gnome-keyring. disable it will be fine.

i removed every apps about gconf, i found dbus-x will no start twice. and also gconf-d ; ) so i think it do my own problem. but this is not important.

i tried like you said.

there is nothing about xfce4-session-$HOSTNAME$DISPLAY in ~/.cache/sessions/, just some thunar-xxx. so i didnt delete it.

i removed every files in ~/.config/autostart except xfce4-settings-helper xfce4-tips xfconf-migration, because i dont want to start them when start.

and i add a terminal to autostart though xfce4-settings.

then log out, and log in, no matter though slim or startxfce4, i still found terminal start twice.

i mean only though xfce-session autostart function will cause this. if i add it to .xinitrc such problem will not appera. and the save session function is ok, it works, just when autostart and save session all have a same application, the app will start once.

i hope i explan it clear enough, sorry for my english. you dont have such problem? add a app, and not use save session, then restart, it should appear

Ok, this should be fixed now.

i'll try svn version later, thanks very much for your hard work