Why do I recieve multiple warnings of "No running instance of xfce4-panel was found" when logging into Xubuntu?

I'm running Xubuntu 11.04, the bootup-time is quite fast but when I log in it takes close to a minute before the desktop is displayed, meanwhile I see no activity on the hard drive. When I finally have the desktop I see this notification repeated 10 times:

and then this one:

In .config/autostart I have these entries

$ ls
xfce4-settings-helper-autostart.desktop

xfce4-clipman-plugin-autostart.desktop  xfce-panel.desktop

$ cat xfce-panel.desktop 
[Desktop Entry]
Encoding=UTF-8
Version=0.9.4
Type=Application
Name=xfce4-panel
Comment=
Exec=xfce4-panel
StartupNotify=false
Terminal=false
Hidden=false

I need some assistance to locate the slow startup, which logs to look at etc.

And then this annoying message about xfce-panel. Where do I look for from where it is started.

Solution 1:

According to the questioner, the problem was fixed after removing the .cache folder in his home directory.

In some cases, as described here, it might be necessary to:

• Log out of xfce
• Log in to a bare terminal (by pressing, e.g., Ctrl+Alt+F1 and logging in)
• Delete ~/.cache (just deleting the contents of ~/.cache/sessions might suffice)
• Return to xfce (usually by pressing Ctrl+Alt+F7)
• Log in