Say John... have you ever looked at the noise on your (switching) Lascar power supplies?
I'm using one here to power a PLL and noticed my close-in phase noise was about 20dB worse with the Lascar than with a linear power supply. I'm amazed it makes that much difference!
(It's power supply->maybe 3' of twisted-pair conductors->power connector on board->10uF bulk capacitor -- the current draw on the board is perhaps 25mA or so -- ... and then the various chips on the board have their own 100nF caps nearby. This is only a two-layer board, though.)
---Joel