I just updated Notebook to 3.0v366 per auto-check of new versions. And with this update I’ve had the same frustrating experience of the last bunch of updates. Any of my previously created Notebook documents opens the previous version, not the most updated version (this time kept opening 362, instead of 366).

My troubleshooting steps:
Make sure the version in my dock (shortcut) is the most uptodate.
Click on any of those NB documents and see what the “open with” is and change it to be 366. This is basically ineffective. I can select 366, but it does not stay that way and if I select “change all” the 366 doesn’t even stay selected before I close the Get info window!
When I update I save the newest version to my Applications folder. With all my apps I like to keep previous versions in a folder within Applications. This issue of not using the most current version only happens with NB.
Last time the only way to resolve it was to trash any and all previous verions and empty the trash. What is going on?

[Leopard on iMac PowerPC G5. But was also doing this on Tiger.]