Lightbox2 default size reverts to shipped settings on second click (for HTML content)

The issue I'm having deals with the size of the lightbox. In the Lightbox2 config page, I have set the default width and height to 960x600. When I first click an article everything works great. When I then close the lightbox and click the article again (or click a different article for viewing), it reverts to the shipped settings of 600x400. I can see this clearly by peeking at the outputted markup on each click.

First click:
<div id="outerImageContainer" style="background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); width: 980px; height: 620px; "><div id="modalContainer" style="padding: 10px; width: 960px; height: 600px; z-index: 10500; ">...
(note that the it's 980px and 620px because of the 10px border)

Second click (i.e., closing lightbox, then reopening it without refreshing the page):
<div id="outerImageContainer" style="background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); width: 620px; height: 420px; "><div id="modalContainer" style="padding: 10px; width: 600px; height: 400px; z-index: 10500; display: block; ">...

To adjust the size of the lightbox I went to the Lightbox2 configuration section, the HTML Content tab, and changed the default dimensions to 960x600. Any help would be most appreciated (even if it's an ugly hack -- got to get this fixed!). I'm using Views to display the list of articles. Here is what one of my links looks like (using the "rewrite output" feature for the fields):

Sample link:
<div class="featured-article-subtitle"><a href="node/[nid]/lightbox2" rel="lightmodal">[field_subtitle]</a></div>

Thanks!
woop