Using the Word Suggestion list in Mountain Lion?

Hi, Wondering if anyone else has experienced, and solved, this problem. I just upgraded to Mountain Lion, and have noticed that, in the Text Edit and Mail apps, I can no longer bring up the Word Suggestion List. Under OS-X Lion, after typing part of a word, I could press either "Escape" or "F5", and a menu containing possible word choices would appear. However, under Mountain Lion, this doesn't occur. Instead, the app automatically completes the partially entered word, without providing any options. Is there a means of fixing this, so that I could get the word suggestion list back? Any help is greatly appreciated.