I have been writing complicated code for years without any troubles. Now something simple will not compile correctly. TOGGLE will not toggle low but does toggle high. Everything else seems to work ok but I am worried about this instability -- Rebooting computer did not clear this issue. Ideas on what's going on here?

DEFINE LOADER_USED 1 ' Bootloader space
OSCCON = %01100000 ' Internal oscillator speed 4 MHz 18F4620

MAINLOOP:

' LOW PORTA.0
PAUSE 50
TOGGLE PORTA.0
PAUSE 50

GOTO MAINLOOP