Can't enter blank space with Opera

I am using WP 3.2.1, Opera 11.50, Linux Mint 10 KDE. When try to enter a post using the WP Visual Editor, I cannot enter spaces. I can type “these are words” and what appears on the screen (and in the post) is “thesearewords” When I enter using the html editor, the spaces appear as entered.

I do not have this problem using Firefox 3.6.18, nor does Opera have this problem anywhere else I have used it. (I prefer to avoid Firefox right now because it seems to crash my system.)

I did not find any posts discussing this problem, and would appreciate suggestions as to where I might look for a solution.