Third dealer agrees with me that there is a problem and that skipping a gear probably didn't cause it. It is now grinding 5th to 6th and is difficult to get into 3rd as well.
New transmission has been ordered and will be installed, hopefully, by Friday.
It really sucks that I had to go through all of this trouble just to get a warranty issue fixed. Out of four Nissan dealers that I have dealt with I have only gotten good customer service from the last one. The service manager has kept me in the loop the entire time and they have treated me with respect. Unlike the last three. 25% Satisfaction with Nissan dealers so far.
I also have to say that I am so thankful for good friends. I have been out of town during this whole ordeal and a few friends have been awesome. They have been shuttling my car from dealer to dealer for me. I think I owe them a dinner.