All of your suggestions have not affected the ability to write a post in Internet Explorer. I've been using IE10 since it was released and I run Windows Updates on a weekly schedule. I also run CCleaner, SpyBot Search & Destroy and MalWareBytes weekly. I've made no changes in any settings and yet I was able to post on earlier in the day and now, nothing.
Also, the text box appears in "Visual" mode and I cannot change it back to "Text" mode. None of the editing options will work such as "BOLD", "ITALICS", "FORMAT" drop down menu, or anything else in that pane. If I start a post with a title, the permalink ends in "/?p=1240" or some other ending starting with "p" but no longer contains any of the words in the title.
I can't think of any other symptoms. It's frustrating that I've been able to post 210 items and suddenly I'm somehow blocked in IE10!?!?!