This is the forum version of the screen of death: :)
I just changed my editor mode from FULL WYSIWYG mode to Standard mode in Settings, and I haven't seen the issue again.
In Standard you see all the markup, but at least you can consistently post and edit without losing everything.
Let me know if this also work for those of you who experience the Access Denied issue frequently.
Just wanted to make sure you all are aware that we are discussing this in the main thread related to this issue.