Litter Box help.

Question
I have a 6 month old female mini dachshund that I have been trying to potty train the last 4 months. I live in an apartment ans decided that litter training would be best since she wouldn't have to hold her bladder all day.
Eventually she got to the point where she always peed in the litter box but never pooped. She always pooped in the same 2 spots. I went out of town for 2 weeks and my mom watched her and things went down hill.
She never pottied in the box and would go all over the house including on clothes and beds. Someone even told me to try switching from the litter to a puppy pad in the box and that it worked for them. It's been three days now and nothing. When she does go potty I praise her and give her a treat, when she messes where shes not suppose to I put her in her kennel for time-out, and when no ones home shes in her kennel. I've even been taking her for 20 minute walks, the thing is she never once goes potty on a walk. At my moms boyfriends house she mostly goes outside with the other dogs and goes potty.
But at home I can't find anything to work. I'm at my wits end and need help. I've even been using the spray to make them attracted to the puppy pads, nothing is working.
Any advice you could offer would be greatly appreciated.
Thank you.

Answer
I have never used a litter box, or puppy pads, to house train a dog.  If that is your specific desire, you may wish to contact a different expert on this site.

What I CAN do is provide you with a lot of information on traditional housebreaking.  You don't say how many hours she is left alone per day, but using a crate is an excellent way to teach a dog "to hold her bladder."  8 hours is generally considered the maximum time to leave a dog in a crate.


http://www.ddfl.org/behavior/crate-train.pdf
http://www.hsmo.org/m_obedience/behavior/dogcrate.html

http://www.dogstardaily.com/training/errorless-housetraining
http://www.dogstardaily.com/training/housesoiling
http://www.marinhumanesociety.org/Behavior/Handouts/Housetraining.pdf    
http://www.ddfl.org/behavior/retrain-dog.pdf          
http://www.ddfl.org/behavior/pup-housetrain.pdf