My Code for my school Project is messed up, and I don't know why

Its a long line of code, but I'll point you out to specifically where it is messing up

' {$STAMP BS2}
' {$PBASIC 2.5}
'{1 to 6 with a pause 20 is equivalant to 1 inch)
irDetectLeft VAR Bit
pulseLeft VAR Word
pulseRight VAR Word
loopCount VAR Byte
irDetectMiddle VAR Bit
hit VAR Nib
FINISH CON 4            'Just a constant of if a square is made
turn VAR Nib            'Will increase if a full corner turn is predicted
measure VAR Byte
'===debug variables===
horiz VAR Byte
vert VAR Byte
firstWidth VAR Byte
firstLength VAR Byte
secondWidth VAR Byte
secondLength VAR Byte
 
 

DO
  FREQOUT 8, 1, 43000
  irDetectLeft = IN10
  FREQOUT 2, 1, 42000
  irDetectMiddle = IN0
  DEBUG CRSRXY, 2, 3, BIN1 irDetectLeft,
      CRSRXY, 9, 3, BIN1 irDetectMiddle
  IF (irDetectLeft = 0) THEN 'If the left eye sees a wall, boe-bot goes straight
  pulseLeft = 850
  pulseRight = 650
  GOSUB Move

  ELSEIF (irDetectMiddle = 0)  THEN   'If the front eye sees something, boe-bot will turn to the right
  DO
  FREQOUT 2, 1, 43000
  irDetectMiddle = IN0
    DEBUG CRSRXY, 2, 3, BIN1 irDetectLeft,
      CRSRXY, 9, 3, BIN1 irDetectMiddle
    PULSOUT 13, 790
    PULSOUT 12, 750
    PAUSE 20
    hit = hit + 1
   LOOP UNTIL (irDetectMiddle = 1) 'Repeat the loop until the left eye sees a wall and the front doesn't
  '===If hit is more than 4 then the boe-bot is most likely turning a long enough turn to hit 90 degrees===
 '  IF hit > 4 THEN
 '  turn = turn+1   'Add one to the turn variable to tell how many times it turned
 '  measure = 0    'The measuring resets
 '  ENDIF
 
  ELSE 'Should turn slightly to the left if both eyes don't see anything, just until the left sees a wall
  pulseLeft = 780
  pulseRight = 650
  GOSUB Move
  ENDIF

  '=====Check if Boe-Bot made a square or rectangle====
   IF (turn = FINISH) THEN
   EXIT
   ENDIF
  hit = 0        'reset hit
LOOP

END

'===Statement for printing out the drawing and calculating measurement===
debug_Rectangle:
SELECT turn
CASE 0
vert = measure
firstLength = measure
DEBUG CRSRXY, 0,vert, "|"
CASE 1
horiz = measure
firstWidth = measure
DEBUG CRSRXY, horiz,0,"-"
CASE 2
vert = measure
secondLength = measure
DEBUG CRSRXY, horiz, vert,"|"
CASE 3
horiz = measure
secondWidth = measure
DEBUG CRSRXY, horiz, vert,"-"
CASE ELSE
'When turn = 4, the debug prints out the info
DEBUG CRSRXY, horiz+2, vert+2,"Area is between : ",DEC (firstWidth*firstLength), " and ", DEC (secondWidth*secondLength)
DEBUG CRSRXY, horiz+2, vert+3,"Perimeter is between ",DEC ((2*firstWidth)+(2*firstLength)), " and", DEC ((2*secondWidth)+(2*secondLength))
ENDSELECT
RETURN
Move:
  FOR loopCount = 1 TO 5
    PULSOUT 13, pulseLeft
    PULSOUT 12, pulseRight
    measure = measure + 1   'Counts how many inches is traveled
    PAUSE 20
    NEXT
RETURN

Here is where Its messing up

DO
  FREQOUT 8, 1, 43000
  irDetectLeft = IN10
  FREQOUT 2, 1, 42000
  irDetectMiddle = IN0
  DEBUG CRSRXY, 2, 3, BIN1 irDetectLeft,
      CRSRXY, 9, 3, BIN1 irDetectMiddle
  IF (irDetectLeft = 0) THEN 
  pulseLeft = 850
  pulseRight = 650
  GOSUB Move

  ELSEIF (irDetectMiddle = 0)  THEN   
  DO
  FREQOUT 2, 1, 4500
  irDetectMiddle = IN0
    DEBUG CRSRXY, 2, 3, BIN1 irDetectLeft,
      CRSRXY, 9, 3, BIN1 irDetectMiddle
    PULSOUT 13, 790
    PULSOUT 12, 750
    PAUSE 20
    hit = hit + 1
   LOOP UNTIL (irDetectMiddle = 1) 
 
  ELSE   pulseLeft = 780
  pulseRight = 650
  GOSUB Move
  ENDIF

What's happenning is the Middle Sensor goes extra buggy and crazy. It isn't properly detected 1 and 0. I don't even know why.