> Hi, some time ago somebody claimed that the Frequency to PLL
> can only be 4 MHz...
> Could this be the issue?

Well, this is very interesting. A valuable waste of time, if one could
say that ;-)

Using a 3.2768MHz on OSC1/OSC2, no matter what TMR0 is
loaded with, in whichever order, the period is always 757.85us

So I put a 4MHz crystal in and got these results (give or take a
smudge for calls etc). 83.333ns instruction time @ 48MHz

TMR0 free-running, 5432us. Which is, ta da, 65536 * 83.333ns
TMR0 loaded with FB28 (- d1240) => 104us

So the story seems to be, going back to the 3.2768, that the
PIC may execute instructions at less than 48MHz derived from
OSC1/OSC2, but TMR0 won't work properly. Probably
other modules too

As brought up in a previous thread, the correct way would be
to use OSC1/OSC2 just for the USB and the frequency for
the core and peripherals via T1OSC


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