horse will no go

Question
I have a new quarter horse paint mix. She is a 10 yr old mare.  She is very sweet natured but does not appear to enjoy being ridden.  My husband and I have now ridden her about 5 times.  Twice we have gotten her saddled, gotten on her and she will not move.  No matter what we try, she simply stands still.  The other three times, she was perfect and did everything we asked of her.  Also, she tends to want to start walking when we place our foot in the left stirrup to mount.  It does not appear that she was ever trained to halt during the mounting process.  How do we correct these behaviors?  Thank you!

Answer
As for the walking while mounting - have someone else hold the horse still while getting on.  Overtime she will realize that is what you want.  If you can't have anyone hold her then shorten up your reins as you are preparing to get on and when she goes to step forward pull back a bit on the reins and say woah or if necessary a sharp voice and a quick woah.  If this not enough for her you have a few options.  Some people prefer to use a bit of a crop to sharply strike their chest as the horse attempts to move forward.  I sometimes will just mount anyway.  However, the best thing for me has been the reverse method.  If he does steps forward, back her up!  Back her up a foot.  If she persists, back her up three feet. If she persists back her up 10 feet.  

As for her not going anywhere - having the information that she sometimes walks while mounting and other times refuses to move, she is most likely feeling discomfort from her tack.  Check to see the girth isn't pinching any skin and try pulling her front legs forward to help her.  Check to be sure the bit isn't improperly placed in her mouth.  Check that her bridle isn't to tight.  Check that the girth isn't too tight without it being too loose.  Also take a look at her hooves.  Make sure they clean and there are no rocks stuck and causing pain.  If everything checks out okay, then her discomfort might very well be from a sore back or an improperly fitting saddle.  A trainer or a saddle shop can help you to determine if the saddle is fitted properly.  A local vet can help determine if your horses back needs a chiropractic adjustment or if she needs some massage therapy.