I'll save you the time... These are the headlines. For the background, have a look in the manual for yourself:
Subject:
Reduced Engine Response Times
Reason:
This bulletin informs 737NG flight crews of slow engine acceleration following thrust reduction at cruise altitude due to a recent EEC software update. The bulletin provides suggested techniques to help prevent excessive airspeed loss.
Operating Instructions
Pilots may want to use the following techniques to avoid excessive speed loss due to slow engine acceleration:
1. Use the autopilot and autothrottle as much as possible.
2. When established at cruise altitude, manually select either CLB or CONT on the FMC N1 Limit page. This will ensure maximum available thrust.
3. If the airplane experiences a sudden increase in airspeed that causes the autothrottle to reduce thrust, manually guard the thrust levers to maintain a minimum of 60% N1, if possible. If thrust is reduced below 60% N1, a significantly longer time will be required for the engines to spool up if the time at idle thrust is less than 60 seconds.
4. If the airplane experiences a sudden increase in airspeed, consider using smooth extension of the speed brakes to increase drag and to avoid large thrust reductions.
5. No specific crew actions are needed if the thrust remains at idle for longer than 60 seconds or if the descent is to an altitude below FL300. Normal engine acceleration can be expected in these cases.