I noticed that with the preview pane disabled (I have never used it since it is a huge security and virus risk) that I could not read any emails. Clicking on entries in the inbox had no effect (no email, no error message, just nothing).
It finally occurred to me that this could be another user interface design flaw and went looking for a way to get the emails to display. I found that disabling the popup blocker (in Internet Explorer 10) would make OWA usable again.
There should at least be a warning message about OWA not working if the user tries to open an email and the popup blocker is enabled.