No, the regulator is far from being hot. It is supplied from 12V, on my desk it is a proven good switcher; but the circuit draws some 50mA, power loss is not an issue.

I still think they are rejects, reagrdless of that they "fit" within the specified 5% (or, slightly less at room temperature, but still these pieces fit in). Pity they won't drift more when baked, I'd have an excuse to dump them at the supplier... :-)

Yes, as a wrote above, there was some 200mV p/p noise measured at the reset's supply terminals, most of it at 66MHz (3rd harmonics of the oscillator). Some of it is crappy design (decoupling cap too far from that supply pin which is next to the oscillator). Some more little excuse for the designer: this was a redesign and the predecessor of this circuit was based on AT89C4051 - I checked, that one does not exhibit the noise at 66MHz. I'd guess that this might be due to the faster process used for uPSD3212 (which is specified to go up to 40MHz).

JW