just wanted to chime in with something else here
in proton basic (picbasic) the high and low commands generate two assembler instructions, the first clears the approriate TRIS register (sets the pin as output) and the second sets or clears the output register
I've noticed using HIGH and LOW without some delay, will cause the pic to fail to set the proper output state
I usualy setup my tris registers ahead of time, with the tris instuction, and then use PORTx.0 = 0 or PORTx.0 = 1 to set or clear the output register, you can also use SET PORTx.0 and CLEAR PORTx.0 if that makes more sense