Membership Login widget is setting input element to "focus" on page load in Explorer 11

I have the membership login widget in my site's primary sidebar.

The input element with id "wp-submit" is somehow in the "focus" state on page load in IE11. I don't see this behavior in the latest Chrome or Firefox on Linux or Windows, although I haven't subjected it to full browser testing.

This causes a problem in that the browser automatically forces the page to scroll so that an element that is in focus on load is in view on the page. Since my widget is underneath some other sidebar widgets, this means that the browser automatically scrolls down from the top of the page on load.

I've added a screenshot - as you can see, the "log in" button is in its focused state.