I have run into this situation on the last couple of flights, where I should be descending to make a normal approach, yet I never seem to get some sensible descent instructions. I wind up having to use the speed brakes on the NGX, in order to get down to a normal approach altitude. Today, I decided that from now on I would insert an altitude, around 70 miles from the airport that would get me down in plenty of time, so at the waypoint Lasko I set the altitude at 12,000feet. Now I am approaching Lasko, after getting initial descent assignments of 29,000, and flying closer and closer to Lasko, contacting ATC with position reports in case they forgot about me, and finally see that I am 11 miles from Lasko and distance is closing and I am still at 29,000 feet. I check say it again, to see if I missed something, and the last communication from ATC was to descend to 29,000. I finally set the 737 for a steep descent, apply the speed brakes, and start diving for the airport. I then switch to approach, and the first comm I hear is for me to climb back to 29,000 which I ignore. Then I ask for pilots discretion approach and am cleared for the approach.
It seems that the only problem I have on occasion with PF3, is descending for a normal approach. Everything else works perfectly, but as I approach and airport, I am always wondering "what is going to happen this time", which shouldn't be. Sometimes it works, but too often, I see this problem. Can you look at the log and see if I am missing something?