I have used the new 18F8723 with 12 bit A/D.

To get the the full resolution, you have to use DEFINE

"DEFINE ADC_BITS 10"

Because PBP only "knows about" 8 and 10 bit converters.
If the DEFINE is missing or not interpreted properly in the
compiler, it will default to 8 bits.

If you use the line above at the top of your program,
and have a 12-bit converter in your chip, the result will
indeed have a full 12 bits of resolution.