ok, i've tried to determine where this curious message come from:
this message also occurs when you just type "opkg update":
root@et9x00:~# opkg update
Package enigma2-plugin-extensions-mpdcontrol version 0.1-r2 has no valid architecture, ignoring.
Downloading http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/3rd-party/Packages.gz.
Inflating http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/3rd-party/Packages.gz.
Updated list of available packages in /var/lib/opkg/openpli-3rd-party.
Downloading http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/all/Packages.gz.
Inflating http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/all/Packages.gz.
Updated list of available packages in /var/lib/opkg/openpli-all.
Downloading http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/et9x00/Packages.gz.
Inflating http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/et9x00/Packages.gz.
Updated list of available packages in /var/lib/opkg/openpli-et9x00.
Downloading http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/mipsel/Packages.gz.
Inflating http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/mipsel/Packages.gz.
Updated list of available packages in /var/lib/opkg/openpli-mipsel.
so i take another try with "3rd-party-feed.conf" renamed into "3rd-party-feed.conf.bak" resulting into the message
root@et9x00:~# opkg update
Downloading http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/all/Packages.gz.
Inflating http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/all/Packages.gz.
Updated list of available packages in /var/lib/opkg/openpli-all.
Downloading http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/et9x00/Packages.gz.
Inflating http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/et9x00/Packages.gz.
Updated list of available packages in /var/lib/opkg/openpli-et9x00.
Downloading http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/mipsel/Packages.gz.
Inflating http://downloads.pli-images.org/feeds/openpli-2.1/et9x00/mipsel/Packages.gz.
Updated list of available packages in /var/lib/opkg/openpli-mipsel.
the message about the invalid architecture of the mpdcontrol-plugin disappears. Why? I don't have installed somethin like mpdcontrol?
Is there something wrong in the 3rd-party-feed?