House-broken dog erratically urinating in house

Question
My wife and live with 2 cairn terriers and 1 house-cat.  The terriers are about 1.5 years old each and for the most part are well behaved dogs.  They are crate-trained and can "hold it" for a considerable amount of time while inside their cages.  

After letting them out of their cages, they immediately are taken outside and typically do their business without issue.  Unfortunately after they do their initial business from being inside the crate, their peeing schedule goes out the door.  We try to take them out often enough to do their business outside, but without fail, our one female terrier seems unable to hold it inside the house. It's never in the same spot typically, we constantly scold her for doing so, we immediately clean it up after we send her outside, but it's getting beyond frustrating right now.  The worst part is, she knows and understands that it's bad for her to do it in the house. She always cowers, runs away, and attempts to hide right after peeing.

As a prime example of this situation.. we recently were watching a movie in the living room one evening and noticed our female dog drinking water.  We let her outside approximately 20-30 min later to use the restroom and run around some. About 40 minutes after that, we let her and our male terrier inside the house to spend some time with us.  Less than 5 minutes inside the house, she pees, then runs to her crate with her head down. Why she felt suddenly necessary to pee inside rather than outside, or why she could not hold it while inside I can't seem to figure out. She never spends any time inside the crate on her own free will, only when she pees in the house and knows she will get scolded for it.

Our other dog is very behaved and rarely has a mistake.  OUr female seems to do this quite often and without any apparent reason.  I have taken her outside at times and stood with her for 10-15 minutes to use the bathroom and she doesnt seem to need to go.  Once i bring her inside, 2 minutes later she has peed on the floor.  

We have tried positive reinforcement for going outside, we give her treats for doing well, we scold her verbally for peeing inside, and she is crate trained without any problems there.  We just have NO idea why she continues to pee inside the house, at random spots, at random times, and for no apparent reason.  She can hold it for HOURS while in her crate, but cant hold it for 15 minutes if she just running around the house.

As a side note, she does have a lot of energy, and is young, but so is our other terrier and he is fine for the most part.  We are on the verge of going crazy and wish someone could offer some advice on how we can fix this situation.  Our carpet has been single-handidly ruined by her and we're fed up..

Should we contact a professional trainer or is there some way we can correct this problem without the help of a professional.  Any suggestions or help would be greatly appreciate. Thank you

Answer
You may have to have a professional observe exactly what is going on.  Perhaps you should start with a check up at the vet.  

Obedience training sometimes helps.  The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/ For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm