how did you validate the javascript?
I didn't. IE6 reported the error (lower right - status bar). Unfortunately, it never offers much in the way of additional information. However, since I didn't get a similar report in IE7, I assume it's an IE6-specific issue.
present location of the search bar on 9001ventures.com is working fine in the sidebar, however, I cannot get it to work in the nav bar
Ah! I've had a look at your searchform.php and I can't see anything within it that would cause a problem, so I think it is indeed a CSS problem. Unfortunately, it's impossible to summarise the CSS differences between Firefox and IE7 because so much relies upon the context in which the relevant styling is applied. I normally carry out all the initial work in Firefox and then apply fixes for IE via a conditional stylesheet - which you said you have in place already (albeit empty).
You say that the the searchbox "doesn't work" in IE. In what way? Could you place the search form back in the nav bar so I can see it on the site? If this is a CSS problem, it could be as simple as applying a little extra positioning via the IE specific stylesheet. However, I'd suggest that you first get all of the inline styling out of searchform.php and into your main stylesheet. It will make applying additional CSS so much easier.
SEARCHFORM.PHP
<form method="get" id="searchform" action="<?php bloginfo('url'); ?>">
<div><input type="text" value="<?php the_search_query(); ?>" name="s" id="s" />
<input type="submit" id="searchsubmit" value="Search" /></div>
</form>
CSS
#searchform {
text-align:right;
margin:0;
padding:1px;
}
#searchform #s {
width:125px;
}
Once that's all in place and the search box is added to the nav bar, I'll have a look and see if I can come up with some suggestions.