Will, not sure what you are doing, but I have no problem climbing the SF50 to FL280. I would look into that if I were you.
jroberts, please, oh please can we speed up the implementation at least of the GPS. Trying to do long flights using only VOR's is starting to bore me, and stress me out at the same time. Besides the 737, what sold me to buy this, was the fun I could have flying the SF50 on longer flights, and was disappointed you released the sim without a working GPS system on a VLJ I really looked forward to flying. Just a small update involving this besides waiting for the next major update would be the best!!!