The first thing to ask is did you tune it? If not well strings stretch and change with temperature and humidity tuning before playing should be done on a regular basis.
Well the KA CEM has geared tuners... so if you tune it and it keeps going flat its not like its a loose friction tuner. How many times does the string wrap around the post? If its wrapped over itself it can cause tuning issues.
My KA SEM came with Aquilas on it, I changed them over to Aquila reds and will never go back.
Another thought you're off an octave on that one string?
~good luck
EDIT: Forgot to ask of the damage from dropping the instrument where did it take damage?