You have to manually change file /share/enigma2/keymap.xml, but be carefull, you could be unable to use img again, make a backup copy of that file before change it.
Thanks very much for your angle Tamaki, it works now after change 2 lines at the keymap. Now I can access all the apps/extensions/addons quickly by a brief press on the BLUE button.
I did:
cp -p /share/enigma2/keymap.xml /share/enigma2/keymap.xml.orig
vi /share/enigma2/keymap.xml
Change the following 2 lines from:
<key id="KEY_BLUE" mapto="DeliteBpshow" flags="b" />
<key id="KEY_BLUE" mapto="extensions" flags="l" />
to
<key id="KEY_BLUE" mapto="DeliteBpshow" flags="l" />
<key id="KEY_BLUE" mapto="extensions" flags="b" />
"b" may stand for "brief" (or "breve" on Italien) , "l" for long press.
Reboot
You could use "total commander" or "vucc - vu control center" to download the file and then modify it by using notepad.
NB: very strange after the reboot I lost the network, I reboot the router and powerline/homeplug and my Vu uno, then everything is ok again...maybe just a coincidence
Thanks
van12