Yes, the events do appear now. But...
most of the mandetory fields are missing: e.g. name, address, company & email address and so.
Plus, When I do register for an event (try one on the 16th of December 2010), I do not get a confirmation email.
Could there be a chance that when I upgraded to 2.7 --> downgraded to 2.6.9 my SQL table was screwed up?
I'm having the same problem. Mandatory fields are missing and the tab that allows you to edit those tabs whether they should be mandatory or not is missing from the configuration tab.
Yes, the most likely cause of this issue is that your categories are unpublished. If the category is unpublished, all of its events will not show up.
palookabui - regarding the fields, this issue was fixed in the last 2.7.0b update. However, ALL fields are now controlled in the fields manager. First, download and reinstall 2.7.0b. Go to the Fields manager and make sure your fields like firstname, lastname, email, etc are showing there. Then go to your events, and find the Fields tab within the event. Make sure the needed fields are enabled for the event. There is no Fields tab in Configuration anymore. That's not a bug... it was purposely removed... never to appear again