[xbs08]

Have the same problem with my Samsung HDTV HD Ready and the NUC.

HDMI #1
Can access bios but every time the NUC boots/reboots the Just Scan (1:1) setting is lost and have to cycle through 4:3 16:9 Zoom and Finally Just scan.
This only happens when the resolution is set to 720p or 1080i, if I use the native res 1366*768 the Just Scan settings sticks between reboots.
HDMI #1 has a label that reads "PC", supports external audio sources (for DVI) and some PC resolutions e.g. 800x600, 1024*768.
One big problem with 1366*768 is that it only supports 60Hz, so adjust video to screen doesn't work, while 720p supports 50Hz/60Hz.
Got around this issue with suspend/wake, if the NUC suspends the Just Scan setting sticks, it's only lost in boots/reboots.

HDMI #2
Can't access bios because as it doesn't support low resolutioons, only supports 720p/1080i/1366*768.
Just Scan setting sticks between reboots and also with suspend/wake.

Overall image seems sharper/better in 720p and the NUC switches between 50-60Hz just fine based on the playing material.
In 720p the Just Scan settings is lost if the NUC reboots, it sticks when using Suspend/Wake though.
In 720p only 1080p material is resized while in 1366*768 both 720p and 1080p material are resized.