[SOLVED] Black "point" next to logo

Hi,
I have black "point" next to logo image (see attached image), this is not part of logo picture, but it moves when I change position of the logo. Url: http://rcs.cz/rr2/ (ATH 3.7.7, WP 3.4.1).

HTML/CSS Inserts/Since 3.6.5 PHP code cannot be used anymore in HTML/CSS Inserts:
h1 { font-size: 34px; line-height: 1.2; margin: 0.3em 0 10px; }
h2 { font-size: 20px; line-height: 1.3; margin: 1em 0 .2em; }
h3 { font-size: 24px; line-height: 1.3; margin: 1em 0 .2em; }
h4 { font-size: 19px; margin: 1.33em 0 .2em; }
h5 { font-size: 1.3em; margin: 1.67em 0; font-weight: bold; }
h6 { font-size: 1.15em; margin: 1.67em 0; font-weight: bold; }
div.widget ul li { margin-bottom: 5px; }
#header_image_overlogo { position: absolute; height: 0; top: 1px; left: -31px; z-index: 99; }

Same point I have also on other website (ATH 3.7.6, WP 3.3.2)....

Thank you for help!
Best regards
Jan