Version 22.214.171.124 on 64-bit Windows 7
In the following Perl example, if you place you cursor after just after the else, and press the space bar (in order to insert a comment), the cursor won't budge. If I type another char, like the "#" for the comment, I can then insert a spaces. Once or twice I got a pop-up about syntax expansion which I'm guessing is playing into this.
if ( $x )