Strange javascript rendering problem

I've got a situation here that seems quite complicated. I'm working on cleaning up an XP machine where the home page is http://news.google.com. This page has a "News" button near the top-left, and clicking on it produces a drop-down menu of stories that are usually hidden. This function was working fine on the machine in both IE7 and Opera 11.52, but after eradicating viruses, evidently something was changed so that IE no longer hid the menu. Instead it became a left column, squeezing the main column into a tiny sliver. Opera still displayed the page correctly. And in both browsers, clicking on the button still produced the hidden menu.

However, checking the page on my Vista machine, I find that not only does IE(9) not render the menu as hidden-only, but Opera (11.60) also doesn't. Perhaps that's an Opera version thing in action? On this machine Google Chrome displays the page correctly. I don't have Opera 11.52 on this machine to test it.

I'd like to get this page working correctly in all browsers, and thought that maybe someone here would understand what's going on.

Thanks,
p.

The code behind the button is:

<div><span class="hidden-story-msg">Click "Show Hidden Stories" at the bottom of the page to view deletions.</span></div></div></div><div class="nav nav-one-col-hp jfk-scrollbar-borderless" id="left-nav-wrapper"><div class="browse-sidebar"><ul class="nav-items" id="anchorman-two-browse-nav"><li class="nav-item nv-FRONTPAGE topic-nav-item"><span class="sel"><img class="chip nav-0" src="http://www.gstatic.com/news/img/cleardot.gif" width="6" height="13" alt=""><span>Top Stories</span></span><div class="topic-list"><div class="topic"><a href="/news/section?pz=1&cf=all&ned=us&hl=en&q=topic:sylvester_stallone&topicsid=FRONTPAGE&topicnv=__AB21PFwCF9ttzeLfnWWV7BnIwbjPHz21x884YJaZ5hN8zt3uZV2eDVAIowVZVpTED1_NjLtoXOtkc0YzdaiLeuaJsJ67JOCMw4TWFGkWdOOzSgmVquul7tvaO657uBrIVzWOpmaJhD-TCDfzTmBWkCz4PWojHDNqa6SUOlwBDgkOAmdEynOcevya-5kltSd9dBA2kIEf3TKXcakgTnc1ea8xTeHUGDVLt6_LUsHRjmrcCLLt4EXjRnJcWa91cz9F9Uafc0528xllcIdqeOviYF15ZREQxU9_DfwkJOqdVmcTbgbszpf6xU590c5RZLYZDY0c4Ol0rlXIyoQhtZ9la7vPZrGJsI_a-NdTZJTKOsi3XhlMqlJhei94BHuBnkgQAFZ_1OPGPI52kb3zu8Tx3vl69T6SGXz_OLxWQQyxm3JlJ6gpRQjP7zKmxEW9Ojax-qiicPfTlp00w1u68pcMhMC6SiI_8qjoYuUEpE7rIWbP_Dmit1cPl0wf7m0Wm8laL5iieJcxbQwEExwuAKGfq7CaS-rNDiMIf4gmaGTc_lXepe7jdf374PYzljbZ0nznitqtdVoHt7COzlAX850buA7PTG07j9Bi2kgBfe9Zwv_IZ7aRb5xSuqC3O6DZqiuIRtL8lgi9neRCziJTBRc2_ztzZbWfXH-xpzCUrGpByz6PMjdY62D5ObGGBVMf_9ypkuixOwK4EslCHCS4nytZeVIWcwAbFBTtgZ0aO5YHmc2iSXrD2kqwSbmvvHG3ZcZfNsAlkQQtSLDfjKVmsM2cFxuDp1-F7VuGcg%3D%3D&ict=tnv0" class="persistentblue">Sylvester Stallone</a>
</div>

I just tested the page on a laptop also running Opera 11.60, and that one rendered the page correctly. There doesn't seem to be any rationale to why this page doesn't render in some installations. All installs of Opera allow all JS options except lowering/raising of windows and the error console.