Sorry I missed this thread and did not see it until you figured it out I might have saved you some time and aggravation. I am glad you got it fixed.
I had the same problem and the transmission mount was the problem. I made a thread about it a while back so I added the link below in case anyone is interested in what I found too.
http://www.vehicross.info/showthread...t=transmission

Also if anyone is interested Joe Darlington makes a poly transmission mount, we bought 2 of them and they are nice, PM him if you need or want one.
http://www.vehicross.info/member.php...Joe-Darlington