I spend time with this "killer" code. Now I discover another strange phenomenon : anything I do, can't generate "train" of pulse.
Instead generating for 4 times this sequence : high 2650 ,pause 2500, high 660, pause 100
I have just ONE sequence for about 42.25 mS !!!
WHY ?!?
Code:
main:

zecime  CON 106    '// = ( 106 * 25uS) = 2650 uS burst
unu       CON 24     '// = (24 * 25uS) = 0.60 mS burst
delay     CON 104


i 		var byte
cycles	var byte
acycles      var byte

;============================
Main:
IF but1=0 then 			; VOLUME UP
    goto ir_send
endif

Goto Main

'=========================================
ir_send:
     	cycles=zecime
        acycles=unu
 for i=1 to 4        
        call Pulse
        pauseus  delay        
        call Pulser
 next i     
Pauseus 100   
Goto main        ' or Return, have no result !

Pulse:              ' Generate "Cycles" number of 40kHz pulses
ASM
   bsf gpio, 2     ; 1uS, LED=on
   goto $+1         ; + 2uS = 3uS
   goto $+1         ; + 2uS = 5uS
   goto $+1         ; + 2uS = 7uS
   goto $+1         ; + 2uS = 9uS
   goto $+1         ; + 2uS = 11uS
   goto $+1         ; + 2uS = 13uS   
   bcf gpio, 2     ; 1uS, LED=off
   goto $+1         ; + 2uS = 3uS
   goto $+1         ; + 2uS = 5uS
   goto $+1         ; + 2uS = 7uS
   goto $+1         ; + 2uS = 9uS
   decfsz _Cycles,f ; + 1uS = 10S    
   goto _Pulse      ; + 2uS = 12uS
   return           ; Add 2uS for return to caller    
ENDASM


Pulser:              ' Generate "Cycles" number of 40kHz pulses
ASM
   bsf gpio, 2     ; 1uS, LED=on
   goto $+1         ; + 2uS = 3uS
   goto $+1         ; + 2uS = 5uS
   goto $+1         ; + 2uS = 7uS
   goto $+1         ; + 2uS = 9uS
   goto $+1         ; + 2uS = 11uS
   goto $+1         ; + 2uS = 13uS   
   bcf gpio, 2     ; 1uS, LED=off
   goto $+1         ; + 2uS = 3uS
   goto $+1         ; + 2uS = 5uS
   goto $+1         ; + 2uS = 7uS
   goto $+1         ; + 2uS = 9uS
   decfsz _Acycles,f ; + 1uS = 10S    
   goto _Pulser      ; + 2uS = 12uS
   return           ; Add 2uS for return to caller    
ENDASM
Thanks again for attention !