Hi, thank you for your reply.
I have thoroughly checked everything again, and I was on the edge of going crazy
when I realised what was the mistake I made and where.
I tried over and over again and for like the 100th time I saw that until now
I always moved the minifigure's arms by releasing the torsos first. And THIS
is a mistake . Once I released the torso all the parts included in it appeared
on the right side list as unavailable within the given palette. Meanwhile if
I move them without releasing them first they will be OK. So all my issues originated
from this.
As for the LEGO News, now that must have been some sort of glitch or similar,
as once I deleted the part completely and re-added it from the list it was fine.
Maybe you had it in the wrong colour? (It can be easy to recolour a part.)
So now I am error free and cannot wait the middle of May!