Your use of AND is unusual.

IF PORTB.7 = 1 THEN
PORTB.6 = 1 AND POT0 = 25
ELSE
PORTB.6 = 0 AND POT0 = 0
ENDIF

I would use

IF PORTB.7 = 1 THEN
PORTB.6 = 1
POT0 = 25
ELSE
PORTB.6 = 0
POT0 = 0
ENDIF