Gday CIRE
One possible problem and one definite.

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Pot PORTB.2,255,b0 'read first cds sensor
pot PORTB.3,255,b1 'read second cds sensor


if b0 = b1 then start 'if equal do nothing
if b0 > b1 then greater 'if greater, check how much greater
if b0 < b1 then lesser 'if lesser, check how much lesser

if PORTA.1 = 0 then face_east 'limit switch1
if PORTA.2 = 0 then hold 'limit switch2
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1) possible
in yr above code, if bo=b1 you will loop endlessly. Try getting an LCD to output the actual bo and b1 values, to see what you are actually getting

2) definite
The three "if B0.. " lines cover all options, and result in branches to other labels in the program
as such the two lines you added can never be reached and therefore will never be executed. Hence have no effect on basic program you started with.
Andrew