potty training a dog

I need some serious help in this department. I am about ready to strangle the dog. Gidget has been potty trained for a few months now. For some reason the past few weeks she has decided to go in the house again. I've about had it! Natasha (my roommate) and I have been trying to figure out why she is being such a pill lately. Both of us have been gone more this past month, so maybe she hasn't been getting enough attention, right? We thought maybe she was trying to punish us for that. We have been extra attentive while we are at home (the same usual hours as before) but she is still lashing out. She is intentionally going potty in the house. The other day we had gone on a walk and to the park for an hour. I brought her home, left for about an hour, came back and she had pooped on the hardwood. Another time, Gidget had peed in the house, so Natasha put her in "time out." We keep her outside except for the her cage which she can come and go freely into that from outside. Natasha and Blake had gone to the temple and did some errands. She came home and felt terrible that she had put Gidget outside. She brought her in, and immediately Gidget peed right in front of the doggy door. Again, yesterday, I was doing some laundry and Gidget decides to pee on my carpet. This morning I woke up to a pile of poop on my carpet. Good thing I put my glasses on or else I would have stepped in it. I don't know what to do. The "time out" sessions are not teaching her anything. Please give me some advice before Gidget goes to doggy heaven.

Gidget pouting!