widget functioning

I am not using the widgets function (2.8.2) because it seems to apply only to the sidebar. Rather, I am copying and pasting code for AddThis widgets into various files/places within the blog, including the sidebar (http://www.waggleweight.com/blog/). Clicking on these widgets opens a popup window.

On some computers/browsers (including my daughter’s), these popups remain centered (or floating) regardless of where one scrolls up or down the page. On other computers/browsers (including mine), the popup moves down when scrolling down and is completely out of screen by the time the page is scrolled about a third of the way down (when we both use IE8). In other words, when the button is placed at the bottom of a page (as in single post pages) and clicked, no popup window is seen unless scrolling to the very top of the page. (It is possible this has been happening in previous WordPress versions as well and I just never noticed).

Is this a function controlled and/or altered by WordPress, and if so any comments on how this problem might be corrected would certainly be appreciated. Could it be related to the “role” attribute in the code, which comes up as being invalid (default theme)? Thank you in advance for any comments.