It's been a long time since I was in a 727 but I can never recall flying at FL350, not that it has anything to do with your problem.

I remember when 767's took over the route that I routinely travel on (YPPH-YMML or YSSY) That we used to rip straight up to cruise altitude of FL390 in 1/2 an hour, compared to wheezing along for an hour or more to get to FL320. I still miss those 727's.