A year ago, there was this topic here: http://wordpress.org/support/topic/removing-the-parentheses-that-display-around-the-read-more-link?replies=6
It's hard to believe, but the OP did not mention the solution.
Now it's my turn to rip the hair out of my head and wonder how to get rid of "(" in front and ")" after the more link.
What I am getting:
What I expect:
OK, while writing this, I found a solution: for v.3.3.1, edit line 185 of wp-includes/post-template.php to remove "(" and ")". Only the extra ones!