[Elecraft] [K2] C22 has no effect

[Steve Kavanagh]

I just acquired a second hand K2 (my second one) and upon going thru the operation in detail I noticed that it was somewhat off frequency.  WWV at 10 MHz is received best (on USB using the CW filter - there is no SSB board) at 10,000.96 MHz and adjusting C22 has no discernible effect on the beat note while listening to WWV tuned slightly off frequency.  I took the control board out and saw that C22 is soldered on both sides.  But the only possible cause I can think of for this behaviour is that C22 is either not making contact (bad solder joint) or is defective.  Am I missing any possibilities ?
 
73,
Steve VE3SMA