docky fails to start caja on mate desktop

1) set docky in mate autostart applications
2) add caja in docky by dragging it from mate applications menu
3) after loging in mate desktop, click on caja icon in docky

expected result : a caja window should open
actual result : no caja window opens

after some investigations, it appears that the problem comes from the fact that docky does not unset DESKTOP_AUTOSTART_ID after startup, while it should (according to caja maintainer, see that thread : https://github.com/mate-desktop/caja/issues/227#issuecomment-31482197)

RELEASES INFORMATION
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this is with docky 2.1.4-1, mono-runtime 2.10.8.1-8 and mate-desktop 1.6.0-3+7.wheezy on Debian wheezy.
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docky -d output :
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[Info 22:08:17.884] Docky version: 2.1.4 Release
[Info 22:08:17.912] Kernel version: 3.2.0.4
[Info 22:08:17.913] CLR version: 4.0.30319.1
[Debug 22:08:18.202] [UserArgs] BufferTime = 0
[Debug 22:08:18.203] [UserArgs] MaxSize = 2147483647
[Debug 22:08:18.203] [UserArgs] NetbookMode = False
[Debug 22:08:18.203] [UserArgs] NoPollCursor = False
[Debug 22:08:18.224] [SystemService] Using org.freedesktop.UPower for battery information
[Error 22:08:18.226] [SystemService] Network Manager is not available.
[Info 22:08:18.249] [ThemeService] Setting theme: Smoke
[Debug 22:08:18.265] [DesktopItemService] Loading remap file '/usr/share/docky/remaps.ini'.
[Debug 22:08:18.271] [DesktopItemService] Remapping 'Picasa3.exe' to 'picasa'.
[Debug 22:08:18.271] [DesktopItemService] Remapping 'nbexec' to 'netbeans'.
[Debug 22:08:18.271] [DesktopItemService] Remapping 'deja-dup-preferences' to 'deja-dup'.
[Debug 22:08:18.271] [DesktopItemService] Remapping 'VirtualBox' to 'virtualbox'.
[Warn 22:08:18.272] [DesktopItemService] Could not find remap file '/home/denis/.local/share/docky/remaps.ini'!
[Debug 22:08:18.275] [DesktopItemService] Loading desktop item cache '/home/denis/.cache/docky/docky.desktop.fr_FR.UTF-8.cache'.
[Info 22:08:18.964] [DockServices] Dock services initialized.
[Debug 22:08:18.980] [DBusManager] DBus Registered: org.gnome.Docky
[Debug 22:08:18.984] [DBusManager] DBus Registered: net.launchpad.DockManager
[Debug 22:08:19.163] [PluginManager] Plugin manager initialized.
[Debug 22:08:19.173] [PluginManager] Processing config file for "Battery Monitor".
[Debug 22:08:19.188] [PluginManager] Processing config file for "Bookmarks".
[Debug 22:08:19.189] [PluginManager] Processing config file for "CPU Monitor".
[Debug 22:08:19.189] [PluginManager] Processing config file for "Clippy".
[Debug 22:08:19.190] [PluginManager] Processing config file for "Clock".
[Debug 22:08:19.191] [PluginManager] Processing config file for "Desktop".
[Debug 22:08:19.191] [PluginManager] Processing config file for "Gmail".
[Debug 22:08:19.192] [PluginManager] Processing config file for "Mounter".
[Debug 22:08:19.196] [PluginManager] Processing config file for "NPR".
[Debug 22:08:19.197] [PluginManager] Processing config file for "Network Manager".
[Debug 22:08:19.197] [PluginManager] Processing config file for "Recent Documents".
[Debug 22:08:19.198] [PluginManager] Processing config file for "Session Manager".
[Debug 22:08:19.199] [PluginManager] Processing config file for "Timer".
[Debug 22:08:19.199] [PluginManager] Processing config file for "Trash".
[Debug 22:08:19.200] [PluginManager] Processing config file for "Weather".
[Debug 22:08:19.201] [PluginManager] Processing config file for "Workspace Switcher".
[Info 22:08:19.353] [PluginManager] Loaded "Clippy".
[Info 22:08:19.354] [PluginManager] Loaded "Desktop".
[Info 22:08:19.354] [PluginManager] Loaded "Mounter".
[Info 22:08:19.354] [PluginManager] Loaded "Trash".
[Debug 22:08:19.424] [MountProvider] Adding Système de fichiers 32 GB.
[Debug 22:08:19.426] [MountProvider] Adding My Passport.
[Debug 22:08:19.428] [MountProvider] Adding Ubuntu 13.10 i386.
[Info 22:08:20.253] [HelperService] Helper added: /usr/share/dockmanager/scripts/hamster_control.py
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