Good news! I figured out both issues with my HD-XA2.
The white snow issue was caused by the Lumagen VisionHDP scaler being turned on before
the HD-DVD player was fully booted up. The XA2 has to be turned on and must go through enough of its boot-up sequence to get to the point where "HD-DVD" shows on the display. Once it's gotten that far, I can turn on the VisionHDP. I'll just have to program the startup macro on my MX-3000 universal remote to start the XA2 and then wait about a minute before turning on the scaler. It doesn't seem to matter whether my InFocus 333 projector is on before or after any of this, btw... it's the scaler timing that's key.
The sound issue was solved exactly the opposite
way: the Outlaw 990 preprocessor has to be on before
the XA2 is turned on. It doesn't matter whether I'm using the SPDIF or 5.1 analog outputs, and it doesn't matter whether the SPDIF is set for Bitstream or PCM.
So to summarize, the startup sequence needs to be:
- Projector (can come on at any time)
- Audio preprocessor/amplifier
- Wait ~ 1 minute
The next test will be whether the XA2 works with the HDMI switcher I bought to switch three of my three high-def sources (the XA2, my DMP-BD10, and my high-def TiVo). I'm crossing my fingers!