At first I didn't have any questions about the OS2008 update for my N800. As I was making a full backup, I realized I need to know what will be saved and what will be lost when I switch over? I know from earlier updates that I have to reload some apps, but are the other peripheral files (Contacts, Settings,Repositories), etc.left alone or is there enough of a difference iin the new OS to make them unusable or unretrieveable?

your mileage may vary, especially as a newer version of the os2008 is now out but i found that if i reinstated a backup from os2007 on os2008 the os was quite unstable. reflashing and starting from scratch and the new os is pretty solid (still the odd app crash or lockup). I belive others here have also reported problems if using a backup.

someone elso may be able to shed more light on weather a specific part of a restore causes an issue or if its just pot luck how smooth it goes.

Generally speaking, backups should be perfectly fine and stable. One thing I did notice was that the RSS feed reader in the latest revision of IT2008 didn't like one of my feeds and kept crashing and that's less a backup issue than just a general bugginess issue (seeing as it's still not fully ready for use yet).

Other than that, I haven't seen any backup related issues.

For me, the RSS Feed Reader in OS2008 crashed on every startup, apparently disliking the feedlist file restored from my OS2007 backup. Thankfully, I don't fully trust the backup utility, so I had also manually copied my OS2007 feedlist file to a SD card before the upgrade.

Deleting the RSS Feed Reader's directory in OS2008 allowed the program to start, and importing the old feedlist file as an OPML file worked. The program works fine now with all my RSS feeds, so something in the backup-restore process must have caused the problem.

Alrighty then... Sounds like it's just a manual RSS feed load from the sites I saved anyway in my browser list from the last time... cool!

Interestingly my rss reader was broken as well with the (now second to latest) version of 2008. I did a clean import and then after about 1 week it started crashing on load.

Restoring the backup (that crashed the device before flashing) after flashing to the most recent 2008 fixed the issue.