My first attempt at burning a CNDV-80MT (East) DVD was successful enough to allow me to complete the firmware update and operate the NAV system. I did eventually find that the POI and Address Search functions worked intermittently - meaning that when it did not work, an attempt to pull up the POI search would just drop me back to the map display.
At one point I thought it may be thermal issues, since it seemed to correlate with extreme cold, and after a length of time the system would become more responsive. I did discover over time (> 4 months) that even when it did become responsive, it seemed to ponder exceedingly long on some letters, and certain search items would always kick me back to the map (e.g. entering "cu" as in "cunningham", or "ku" as in "kumon")
. This in the end convinced me that
my disk burn was faulty (or at least the drive had difficulty reading it), and certain sectors of the database were rendered inaccessible. The disk is a Memorex DVD+R DL, which I created using Roxio Basic v9.0 which came free with my HP Pavilion Desktop PC.
I've now burned a second Memorex DVD+R DL 8X disk using the same Roxio software, this time selecting the options to use the hard drive as an intermediate step in the burning process (even though the .ISO file is already on the hard drive), and closing the file system when completed. When I inserted this new disk into my AVIC N2, the NAV system came up normally, and presto!... the POI Search came up immediately and all previously faulty search terms were immediately found, and not only that, response to letter entries was noticeably quicker... I would even say "snappy!" 
Bottom line tips?
- [*:275qfou2]A Memorex DVD+R DL 8X disk can be made to work.
[*:275qfou2] Roxio DVD Creator Basic v9.0 is an effective DVD-burning tool.
[*:275qfou2]The lengthy burn process requires a stable, undisturbed PC platform to create a good disk (burning at 1X is probably less important than making sure you're not streaming HD video or gaming at the same time).
[*:275qfou2]It's probably a good idea to turn off your screen idle when burning.