-- Vin Shelton <acs(a)xemacs.org&gt; spake thusly: A simpler test is: 1. xemacs -vanilla 2. Insert into *scratch*: ;; ( ;; ) 3. Move point to just after ")". 4. Do: "M-:(scan-sexps (point) -1)" --> Error "Unbalanced parentheses" I just tested this with emacs 20.7 and xemacs 21.1 and got the same behavior. The problem is that scan_lists (which scan-sexps uses) won't find a matching parenthesis inside a preceding comment. You might notice that in your test if you insert an open paren at the start of the buffer and then put the cursor after "x key.)", that the open paren _outside_ the comment is matched. The bug is either in mic-paren or paren or, more likely, in syntax.c. Presumably placing the cursor after a parenthesis inside a comment should either match another parenthesis in the same comment or return 'nil, just as it would if placed after a non-parenthesis. Either way, the bug exists in prior versions of Emacs and XEmacs, so shouldn't affect any decision as to whether to roll back the syntax-table changes.