just for the record what version of alldigital.pbp did you try ? there are a number of versions

First off, ADCON1 = whatever. Don't use it. It'll just screw things up.
is not right ,it just does not do what you erroneously thought it did as archangel says
ADCON1 is where you CHOOSE what your voltage references are & Trigger Select
and needs to set appropriately " rtfm "