>>Any idea whats causing it ...
Wrong syntax.

>> and how to fix it?
Code:
ADCIN 0, ADT[ADCHAN]
-- OR --

Code:
ADresult   VAR WORD EXT
@ADresult = ADRESL

...
ADT[ADCHAN] = ADresult
-- OR --
Code:
ADT[ADCHAN] = ADRESH << 8 + ADRESL
-- OR --

...<br>