> I'm trying to run it at 4 MHz (using a
> crystal and two 15 pF caps).  The operation of the oscillator seems to be
> hit or miss (mostly miss).  I've played around with different parts (I've
> tried a ceramic resonator, different values for the capacitors) and still
> nothing that is reliable.  I have not tried an in-line resistor.
>
> Has anybody else seen this type of problem and if you did, what did you do
> to fix it?

Yes.  Exactly the same symptom I had when I was *sure* the config
bits were set for XT oscillator, but they were REALLY set for LP
oscillator.  This is a new part for you?  Even money the config is
mis-programmed as LP or RC or something, not XT.

I hope I'm right, 'cause its easy to fix by re-setting the config bits
somewhere in the tool chain.  In my case, I had an old #define that
was setting the __config bits incorrectly for the part I was using.

------------
Barry King, KA1NLH
Engineering Manager
NRG Systems "Measuring the Wind's Energy"
Hinesburg, Vermont, USA
www.nrgsystems.com