Are you getting confused by 'left' and 'right' side? By your example it is the A in it's left side (or FIRST position) that is not working.
In a font I'm making, just one kerning class, the _A class, won't kern on the right side with other classes. It will kern with unclassed characters like the question mark. "AVATAYA?" looks like "A VA TA YA?" in the preview window. All the other pairs work correctly, as far as I've been able to determine. Any ideas? Here is the feature code, just as FontLab generated it:
feature kern {
pos F AE -50;
pos F slash -40;
pos P X -50;
pos P AE -70;
pos P slash -50;
pos X Lslash -30;
pos B X -20;
pos x q -25;
pos lcaron q -60;
pos lcaron x -20;
pos tcaron f -10;
pos tcaron p -20;
pos tcaron q -90;
pos tcaron x -20;
enum pos @_A question -50;
enum pos @_A registered -60;
enum pos @_A backslash -70;
enum pos @_A one -50;
enum pos @_A seven -30;
enum pos @_C X -30;
enum pos @_K f -20;
enum pos @_K Lslash -30;
enum pos @_L question -50;
enum pos @_L registered -60;
enum pos @_L backslash -70;
enum pos @_L seven -30;
enum pos @_O X -30;
enum pos @_S X -30;
enum pos @_T q -40;
enum pos @_T AE -100;
enum pos @_T ampersand -50;
enum pos @_T slash -70;
enum pos @_V f -10;
enum pos @_V q -40;
enum pos @_V p -20;
enum pos @_V x -20;
enum pos @_V AE -90;
enum pos @_V ampersand -50;
enum pos @_V slash -70;
enum pos @_Y f -10;
enum pos @_Y p -20;
enum pos @_Y q -30;
enum pos @_Y x -30;
enum pos @_Y AE -120;
enum pos @_Y slash -70;
enum pos @_a f -10;
enum pos @_c x -20;
enum pos @_e x -20;
enum pos @_o x -20;
enum pos @_b x -20;
enum pos @_r x -30;
enum pos @_v ae -10;
enum pos @_v q -25;
enum pos @_quotesingle q -30;
enum pos @_quotesingle x -10;
enum pos @_hyphen X -70;
enum pos @_hyphen seven -30;
subtable;
enum pos F @_A -30;
enum pos F @_period -60;
enum pos P @_A -50;
enum pos P @_period -80;
enum pos X @_O -30;
enum pos X @_S -30;
enum pos X @_C -30;
enum pos X @_G -30;
enum pos X @_J -30;
enum pos X @_o -20;
enum pos X @_e -20;
enum pos X @_c -20;
enum pos X @_s -20;
enum pos X @_a -10;
enum pos X @_y -20;
enum pos X @_hyphen -70;
enum pos B @_A -20;
enum pos B @_V -20;
enum pos f @_a -10;
enum pos ae @_v -15;
enum pos q @_j 70;
enum pos x @_Y -30;
enum pos x @_o -20;
enum pos x @_c -20;
enum pos x @_e -20;
enum pos x @_d -25;
enum pos x @_quotesingle -10;
enum pos ampersand @_V -40;
enum pos ampersand @_T -50;
enum pos seven @_A -50;
enum pos seven @_J -50;
enum pos seven @_hyphen -40;
enum pos seven @_period -60;
enum pos question @_A -70;
enum pos slash @_A -70;
enum pos exclamdown @_T -20;
enum pos exclamdown @_V -20;
enum pos questiondown @_T -40;
enum pos questiondown @_V -40;
enum pos backslash @_V -70;
enum pos backslash @_T -70;
enum pos backslash @_Y -70;
enum pos lcaron @_a -60;
enum pos lcaron @_c -60;
enum pos lcaron @_d -60;
enum pos lcaron @_e -60;
enum pos lcaron [g gdotaccent gcircumflex gbreve gcommaaccent] -60;
enum pos lcaron @_o -60;
enum pos lcaron @_s -60;
enum pos lcaron @_u -20;
enum pos lcaron @_z -20;
enum pos Lcaron @_T -50;
enum pos Lcaron @_V -50;
enum pos tcaron @_a -90;
enum pos tcaron @_c -90;
enum pos tcaron @_d -80;
enum pos tcaron @_e -90;
enum pos tcaron [g gdotaccent gcircumflex gbreve gcommaaccent] -80;
enum pos tcaron @_n -10;
enum pos tcaron @_o -90;
enum pos tcaron @_r -20;
enum pos tcaron @_s -80;
enum pos tcaron @_z -40;
enum pos tcaron @_u -20;
subtable;
pos @_A @_V -60;
pos @_A @_T -60;
pos @_A @_Y -80;
pos @_A @_O -20;
pos @_A @_J -20;
pos @_A @_v -50;
pos @_A @_C -30;
pos @_A @_G -20;
pos @_A @_U -20;
pos @_A @_t -25;
pos @_A @_o -15;
pos @_A @_c -15;
pos @_A @_e -15;
pos @_A @_quotesingle -70;
pos @_A @_hyphen -40;
pos @_C @_A -20;
pos @_C @_V -10;
pos @_D @_A -20;
pos @_D @_V -20;
pos @_J @_A -20;
pos @_K @_a -20;
pos @_K @_o -30;
pos @_K @_e -30;
pos @_K @_s -20;
pos @_K @_c -30;
pos @_K @_t -20;
pos @_K @_u -20;
pos @_K @_v -50;
pos @_K @_y -30;
pos @_K @_d -20;
pos @_K @_g -10;
pos @_K @_hyphen -70;
pos @_K @_O -30;
pos @_L @_T -90;
pos @_L @_V -70;
pos @_L @_Y -100;
pos @_L @_quotesingle -60;
pos @_O @_A -20;
pos @_O @_V -20;
pos @_R @_V -20;
pos @_S @_V -20;
pos @_T @_A -60;
pos @_T @_J -90;
pos @_T @_a -40;
pos @_T @_c -40;
pos @_T @_d -40;
pos @_T @_e -40;
pos @_T @_g -40;
pos @_T @_o -40;
pos @_T @_s -40;
pos @_T @_period -80;
pos @_T @_colon -80;
pos @_T @_hyphen -30;
pos @_U @_A -20;
pos @_V @_A -60;
pos @_V @_J -60;
pos @_V @_a -40;
pos @_V @_c -40;
pos @_V @_e -40;
pos @_V @_d -40;
pos @_V @_g -40;
pos @_V @_n -20;
pos @_V @_o -40;
pos @_V @_r -20;
pos @_V @_s -40;
pos @_V @_u -20;
pos @_V @_z -20;
pos @_V @_y -20;
pos @_V @_v -20;
pos @_V @_O -20;
pos @_V @_C -10;
pos @_V @_period -80;
pos @_V @_colon -50;
pos @_V @_hyphen -40;
pos @_Y @_A -80;
pos @_Y @_J -90;
pos @_Y @_a -70;
pos @_Y @_c -50;
pos @_Y @_d -40;
pos @_Y @_e -70;
pos @_Y @_g -40;
pos @_Y @_o -70;
pos @_Y @_n -20;
pos @_Y @_r -20;
pos @_Y @_s -50;
pos @_Y @_u -20;
pos @_Y @_v -30;
pos @_Y @_z -20;
pos @_Y @_period -80;
pos @_Y @_colon -60;
pos @_a @_V -40;
pos @_a @_Y -40;
pos @_a @_v -30;
pos @_a @_y -15;
pos @_a @_t -10;
pos @_a @_quotesingle -50;
pos @_c @_V -40;
pos @_c @_Y -50;
pos @_c @_T -40;
pos @_c @_quotesingle -40;
pos @_e @_V -40;
pos @_e @_Y -50;
pos @_e @_v -15;
pos @_e @_y -10;
pos @_e @_T -40;
pos @_e @_quotesingle -40;
pos @_g @_V -20;
pos @_g @_j 70;
pos @_h @_quotesingle -30;
pos @_h @_V -40;
pos @_h @_Y -50;
pos @_h @_T -30;
pos @_j @_j 70;
pos @_n @_V -40;
pos @_n @_Y -50;
pos @_n @_v -20;
pos @_n @_T -30;
pos @_n @_quotesingle -30;
pos @_o @_V -40;
pos @_o @_Y -70;
pos @_o @_v -20;
pos @_o @_T -50;
pos @_o @_quotesingle -40;
pos @_b @_V -40;
pos @_b @_Y -50;
pos @_b @_v -20;
pos @_b @_T -30;
pos @_b @_quotesingle -30;
pos @_r @_V -20;
pos @_r @_Y -30;
pos @_r @_a -10;
pos @_r @_quotesingle -20;
pos @_r @_v -10;
pos @_s @_V -40;
pos @_s @_Y -50;
pos @_s @_quotesingle -40;
pos @_s @_v -25;
pos @_v @_Y -30;
pos @_v @_o -20;
pos @_v @_e -15;
pos @_v @_a -10;
pos @_v @_d -15;
pos @_v @_s -15;
pos @_v @_A -40;
pos @_y @_e -15;
pos @_z @_Y -20;
pos @_z @_quotesingle -10;
pos @_quotesingle @_A -70;
pos @_quotesingle @_s -40;
pos @_quotesingle @_a -40;
pos @_quotesingle @_c -40;
pos @_quotesingle @_d -40;
pos @_quotesingle @_e -40;
pos @_quotesingle @_g -40;
pos @_quotesingle @_o -40;
pos @_quotesingle @_z -20;
pos @_quotesingle @_J -60;
pos @_colon @_T -80;
pos @_colon @_V -50;
pos @_colon @_Y -60;
pos @_period @_T -80;
pos @_period @_V -80;
pos @_period @_Y -80;
pos @_hyphen @_A -40;
pos @_hyphen @_T -30;
pos @_hyphen @_V -40;
} kern;
I've also tried duplicating each class into separate left-side and right-side classes, but that didn't make any difference.