Dvorak vs GMAT and GRE

I use the dvorak keyboard. I did not learn QWERTY. I am looking to go to grad school soon and have found that the GMAT and maybe the GRE will not allow me to change the keyboard settings to dvorak during the test. Since there are essays on the tests, and I am required to use one of their computers to take the tests, this puts me at a disadvantage. I was wondering if any of you have heard anything about this since you are a proponents of the dvorak keyboard and I see that some of you may have had issues with this in the past. I told the GMAT people that all I needed to do was change one setting but they still refused my request. I do not want to learn QWERTY just so that I can take a test. If any of you know of anyone that can help me with this issue I would greatly appreciate it. 

Thank you,