I'm having an issue with my navigation screen on my '04 Ultra Lux. When it's on the "map" or disclaimer page, the screen is flickery/fuzzy. The easiest way to describe it is if you're trying to access a channel on your analog TV that you don't subscribe to. Completely unusable. If it's on the "Climate", "Audio", or "Settings" pages it works just fine. I typically wouldn't care, but when the car starts, it defaults to the disclaimer/"I Agree" screen, so it constantly appears broken.

I've looked long and hard but can't really find any threads regarding this issue, which is really the only issue I have (knock wood) with my lovely UL. Thoughts?

 

Sounds like an issue with the Nav unit in the trunk.
Try disconnecting the cables to that clean with spray contact cleaner and then reconnect.

 

Is it easy to access?

 

Easy enough.
See this video at around 3:16 he points to the Nav Unit in the trunk.

 

Can shut off the display. Go to set up. Mine was slow to warm up. The local stereo shop (Sacramento CA) tested and resoldered for $200. Works perfectly.