I played about a bit more and this is what i figured out so far:
When i start PhoCo all my sim contacts are listed under "Tel", which should only show the phone contacts. (my phone memory is actually empty) If i then switch back and forth between phone and sim all names stay listed. If i receive a call in this state then it comes up "call from unknown", with the voice, even tho the nmbr is shown on the phone.
If then i refresh the phonebook (sim shows sim contacts and phone shows empty as it should) and i receive a call, i get the prob as described in the first post. (answer/end buttons show and keeps flashing"reading mobile phonebook)