Transmission Failure problems of the 2007 Lexus RX350

I purchased my Lexus RX 350 Dec 2006. I have 35, 500 miles on my car. My car is used for personal usage. My transmission was recently replaced March 2009. Now I recently had engine failure one month after transmission failure. To make matters worse, I was informed that my transmission is leaking. This problem was discovered after engine failure and replacement transmission.