The datasheet for the PIC18F2520 shows "ECIO" for "external clock with IO on RA6, and the P18F2520.INC file in MPASM sort of modified that to "_OSC_ECIO6_1H", so that's what I used. Using "_OSC_HS_1H", works, but gives me the same 25 second wait at power-up. I'm not using a crystal, I'm using an external oscillator/clock.