3:00 am
If I've got this right, go to Menu, Contacts, No. Screening. There you can add whatever number you like. Calls from that number will not ring or vibrate, but will get added to the Missed Calls list. Text messages will still arrive, and will be placed in the Menu, Messages, Screened Messages folder.
2:56 am
Hmmm... I guess I can't trust stuff I read on the Internet. I just downloaded your owner's guide from Nokia and I can't see anything there either.
I guess if you just want to ignore a certain person, you could add the number to your regular contacts, and set the ringtone to nothing, or a blank recording you make (if the phone supports different tones for each number).
I guess in the mad rush to add more flashy crap, they tend to leave out the more basic functions that are actually useful in a (ahem...) PHONE.