[AUCTeX] Strange icon in toolbar

[Andrej Kastrin]

Dear all,

I compiled the recent AUCTeX (11.86) with GNU Emacs 23 on Mac OS X. Everything 
works perfect, except annoying strange icon in toolbar. The screenshot of the 
toolbar (icon circled in red) is available at the URL:

  http://dl.dropbox.com/u/540963/auctex_toolbar.png

I suppose this is a separator between file management icons (open file, save 
file, cut, paste) and (pdf)latex, bibtex, and preview icons. But isn't this 
separator a bit too wide? I also check this behavior on my Linux machine, where 
this icon is around 1px wide.

Any suggestion how to fix that? Thanks in advance.

Best, Andrej