Dog peeing on Sofa

Question
I am going crazy!  My two year old Wheaten Terrier, Poppet, has always had a problem peeing on soft places (the bed, sofa, back seat of car.) She knows that it is bad, I can tell because she hides right afterward every time.  Most of the time if she has to go out she goes to the door and whines to let me know, but sometimes she just pees.  They are always big spots so it seems like she really has to go and this is not just a bladder infection or something.  Everything in my life has become infused with the smell and I am starting to go crazy.  She is in a crate when I am not home (which she pees in ALL THE TIME.)  I make sure she goes out every five hours.  She was bought from a breeder and she has a happy house when she is not weeing on the furniture so it is not due to stress.  After she pees I spank her to let her know it is not okay, not hard, but I feel like she needs to know it is bad.  Does this contribute to the problem at all?  I wash the sofa cushions in bleach after to get the smell out but maybe she can still smell it, should I get new cushions?  I do not want to drop the money on an expensive trainer but I am at my wits end.  Please, please, please help!

Answer
Hi, Destiny!

First, I recommend positive reinforcement instead of trying to punish a dog.  They really just don't understand it, and I think you will get better results if you don't spank your dog.  When she goes potty in the correct place, give lots of praise, and perhaps an occasional treat (but, no treats at bedtime).  When you catch her going potty in the house, clap your hand or make a loud distracting noise and take her outside where you want her to potty immediately.  I am going to give you a few blog links to look at here, which I believe may help.  Good luck!

http://blog.gizmo2wizmo.com/2009/05/12/5-essential-steps-to-cleaning-dog-pee.asp...

http://blog.gizmo2wizmo.com/2009/02/06/dog-territory-marking--how-to-stop-it.asp...

http://blog.gizmo2wizmo.com/2008/07/28/how-to-stop-your-dogs-submissive-peeing-e...

And one more, just in case your dog is not getting your attention to let her out on occasion:
http://blog.gizmo2wizmo.com/2008/09/13/house-train-your-dog-the-easy-way.aspx