Therem are few postings of that nature but seems like we all have the same problem.. I experince exactly what you have..
to make it going right now.. I do View page from Manage screen and then click on edit (on the page/section being viewed) .. that brings me back to Edit mode and now I can see the text..that seems to temporary fix the problem at least for the page I want to edit..
However, this is defenietly a BUG
