When I generate an SVG image using plantuml.8022.jar, then the following root element is created:
<svg xmlns="
http://www.w3.org/2000/svg" xmlns:xlink="
http://www.w3.org/1999/xlink" height="53pt" style="width:43px;height:53px;" version="1.1" viewBox="0 0 43 53" width="43pt">
While the style attribute sets width to 43px, the width attribute has a value of 43pt; similar for the height attribute.
This inconsistent use of the units px and pt can cause trouble when a browser is used to repesent the generated SVG image. The trouble is avoided, when pt is either replaced with px or when pt is omitted.