I'm not sure if this will help, but if I were you I'd change my throttle climb settings.
1. Try a flex takeoff, i.e. take off with only 75% power (varies, depending on temperature, aircraft weight, runway length, etc.)
2. Do not adjust your throttles during climb unless necessary. Instead, set your IAS bug to 250 KIAS and climb at an angle so that you maintain 250. Once you get to 10,000 feet, adjust this to 320 KIAS. You shouldn't have to adjust your throttles until at least 20,000.
I've seen this problem with another aircraft (Project Airbus A321), and the forum there suggested that I adjust climb settings. In fact, this has worked so well for me that I use it on all flights now. I don't know if it will help you, but I think that it will.