Dog is suddenly afraid

Question
I have a 4 y/o male lab x (fixed)- adopted from the dogs home 2.5 years ago.
He has always been highly strung / scared of a few things (pedestal fans/loud noises/car rides) but none of this has really interfered with his every day life.

For the last two weeks though, he has been afraid of something else in the house, and we can't work out what.

He spends most of his time while he is inside either in our bedroom or study at one end of the hallway or in the lounge room (at the other end of the hall).  At the moment, we can't seem to get him to come into the lounge room from the bedrooms.  He will get to the end of the hall and start to cower/cry and when we force him to go into the lounge room (he has to go that way to get outside), he will slide around on the floorboards (like a cartoon character running on the spot) and race to the door to get outside.  If we do manage to coax him into the lounge room while we are in there, he will pace or sit on his blanket and cry.

His food bowl is in the lounge room and he hasn't been eating well since this all started. My partner and I have been approaching this differently.
-I have been trying to ignore his behavior (he is a Lab, I figure he won't let himself starve).
-My partner has tried feeding him outside a few times, or will stand next to him while he eats in the lounge room and gives him verbal praise (which does seem to help - but I don't want to get him into the habit where he only eats when he is getting attention)

We did move a few items of furniture around (but the behavior started a few days after this) - could it still be the reason?  We have tried moving them again, or putting screens in front of them, but this doesn't seem to help.

Please help!

Answer
Moving furniture CAN disrupt cognition in a dog that has a biologically based problem (eyesight, low level seizure disorder, or acquired conditioned fear response).

Feed the dog IN THE KITCHEN.  Why force him to confront his fear in order to survive?  Makes no sense at all.  Put the food down, take the dog gently to the bowl, LEAVE THE ROOM (do not stand next to him or praise him) and give him 15 to 20 minutes to eat.  Do this twice daily (be sure to measure the amount of food since we want to avoid obesity but that shouldn't prove a problem).

Take the dog to a veterinary behaviorist.  You can find one from the following sites or by calling the veterinary school in your geographical area.  He should be tested for visual acuity, base line neurological response, and comprehensive blood work all to rule out biologic cause.  This professional will be able to prescribe medication that will help the dog to be calmer AND will also be able to make suggestions (having evaluated the dog personally in a thorough manner) to attempt to counter condition him to this room he seems to dread.

http://www.veterinarybehaviorists.org/
http://www.avsabonline.org/avsabonline/

Once we have a result from veterinary consult, we can then attempt to counter condition the dog's fear response (even if there is a biologic cause).  Re-post using followup feature so I can see original question/answer.  Meanwhile, do NOTHING to attempt to persuade the dog to go into or near the area he fears.