I would try clearing the cache "Dashboard->Sitewide Settings->Speed Settings" if you haven't already.

I have tried that. I tried again. Still a no go...

I don't know if you have access to the db but the permissions are set in a table named PagePermissions. The cID column is the Page ID. What do you have for that page

Specifically cgPermissions. And please be careful and don't start editing columns.

Are you refering to the Database Tables and Content section under the Debug tab in Sitewide settings? Sorry, I am brand new to this. :)

That would actually be the underlying database. It was just a way for me to be able to verify for sure that the permissions are being set or not being set. If you don't know what it is, then you are probably better off not doing that.

Could you go to Dashboard->Sitemap. Click on the page and select "Set Permissions" and try setting the permissions there?

That is where I have been trying to set the permission - in the sitemap. I am now trying to go in and edit the page and set permissions there but so far, it is still not allowing the blog page to be seen by guests.

I appear to be having the same issue - I've tried to "Set Permissions" both in the sitemap and on the page specificaly.
I add a new group in this case administrators - check all, save, exit, come back and the group is missing (fyi - tried with other groups)
- also tried making a minor change on the page and the same time to see if all changes were made - yes minor change made.

Wonderiing if this was resolved.

So very sorry it has taken me so long to reply. I did not find a solution for this issue. Since I was just getting started, I reset the site. I imagine that is not useful for you as it required I start from scratch. I do not know what caused that issue. Sorry I could not be more help :(

Follow-up
I'm not sure this is the right solution (or if I have found the cause of the issue).

I came across this quite by accident.
I've been developing on a WinXP Pro computer using IE8 and I happened to be at my Customer site (Win7 Pro with IE9). I was able to change the page permssions and save it on their computer. Returming to the page, the permissions were indeed saved.

I returned back to the office - accessed the page and the changed the page permissions (on my Dev WinXp Ie8) ... and they did not save - in actual fact - all that were enterd disappeared. I then went to my other development computer a "Win7 XP Pro with IE9" and was able to make the page permission changes and they were save.

So .. not sure it this is an issue with MY WinXP Dev computer and/or Ie8 settings. But, I was able to get arround this.

Posting for information only.

I'm having the exact same issue here nearly a year later in 5.6.0.1:

http://www.concrete5.org/community/forums/installation/upgraded-to-...

Did any of you come up with a solution for this? Nobody seems to have any suggestions for me. When I've posted my database contents as discussed above I was told to "stay out of the database".

I can't find any errors logged anywhere. My site is down (to everyone but me logged in as admin), I'm frustrated and at my wits end. I have no plugins or modifications installed.

Not sure if this is the same as my issue. Yours looks like it may be a result of the upgrade. What is your environment - OS and browser?
Try making the change with a different browser IE or firefox(may be far fetched idea.. but all you've got right now.)

Server is CentOS5, webserver is Apache 2.2.3 MySQL is 5.5.20.

Client computer is Windows 7 64-bit. I've tried the following web browsers with the same results in both:

Chrome 21.0.1180.89
Internet Explorer 9.0.8.112.15421IC

As a follow up, my site is now fully functional. With the help of mhawke, everything now works.

See the link above for the solution.

(cliffs: I copied the existing concrete/ folder to a backup and re-uploaded a new one from the github source)