> Cases not earthed -- was not aware that that could/should be
> done

It has fixed occassional mysteries. Personally cured problems
caused by, such as, the position of wiring to an LED display,
and the proximity of a relay

> should have a sine wave, rather than square.  See attached

eeeuuuuwwww. That's overdriven. Did you say this was the first
time you'd used these particular crystals with the 18F ?

Suggests 100k - 200k series resistor

http://www.microchip.com/forums/m313266.aspx

Atmel, but would be relevant to PICs, see Section 4.2

http://www.atmel.com/Images/doc8333.pdf

> In sleep mode, I get the same partial-sine waveform.  If this really
> is the issue now, then why is the wake-mode waveform changing?

Possibly the 32kHz crystal is broadcasting noise into the die or the
primary clock source

Joe
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.