Hello,

I have this problem and I have a clear way to reproduce it.

But first of all, I tried to set runAllManagedModules to TRUE.
I clear my cache and cookies > NO SUCCESS, still the problem.
I tried in private browsing session > NO SUCCESS.

I am using URL Master. When switching URL Master off, I do not have the problem anymore.
The problem only appear on certain kind of page, and I manage to understand in which condition, maybe it can help you to pinpoint the problem ???

1/ Fresh DNN 7.0.0 install (I also tried on 7.0.2 = same behavior)
2/ Install Language Pack (fr-FR for my case)
3/ Enable Content Localization (Host + Admin Settings) / Launch the copy process (copy the english pages/modules to fr-FR)
4/ Install URL Master 2.7.0
5/ Apply changes (HOST > Friendly URL Settings > Apply)
6/ Add a new page, called for example NEWPAGE (do not forget to go to "tab localization" and tick "Create Localized Versions of Page")
6/ Go to ADMIN > Portal URLS
7/ Choose one of your page (for example AboutUs). Copy the name it has been allocated by URL Master (in my case AboutUs.aspx)
8/ Choose you newly created page (NEWPAGE). Add the following URL >> AboutUs/NEWPAGE.aspx (200 OK)
9/ Save redirects and apply changes
10/ Refresh the navigator
11/ Go to NEWPAGE (check the URL is AboutUs/NEWPAGE.aspx)
12/ Try to EDIT the page > nothing happens

IMPORTANT NOTE 1: the same steps reproduced with an existing page does not give any problem (If I rename ContactUs to AboutUs/ContactUs.aspx, I don't have any problem).

In summary, when you use a two level name for your page, and a page is already existing with this name, you can't edit your page.
Example: you have a page called example.aspx and you have another called example/page.aspx, then page.aspx can't be edited

IMPORTANT NOTE 2: when you click ADD MODULES, the module bar appear, and the EDIT icon appear now... Might help you to find the problem ?

Bruce is willing to help, he has already look at it.
DV FX

I had the same issue on Windows 2008 Server. 

I installed the hotfix: 

http://support.microsoft.com/kb/980368  restarted IIS, and joy! No configuration changes.