Hi,
First of all you need to use MPASM for the 18X series, so switch to that if you haven't allready. Then have a look here:

http://www.picbasic.co.uk/forum/showthread.php?t=543

Specificly the post from Steve (mister_e) on 29th october -05.

The latest version of PBP (2.47) hides that warning but I think it's best to get used to the new way Microchip wants it.

Hope it helps!
/Henrik Olsson.