While working my way through the review queue and after I rejected a question, I accidentally did not release my mouse button and proceeded to highlight some text. When that happen the Reject dialog box disappeared and I was left in a broken state that I could not continue with the rejection and could only continue reviewing after refreshing the screen (or hit back on the browser).
I am currently using Chrome 25.0.1364.152 on Windows 7.
This seems like it could be related to this issue Closing popup to reject an edit makes it impossible to approve it without reloading, but that bug was reported as fixed back in September 2012
Here are the steps to reproduce (with pictures):
Start with one standard suggested edit in review queue
Reject the edit
Click anywhere outside the dialog box
Now left in unusable state (can be cured by refreshing and starting over)