I'm seeing all the text in IE6 larger than in Firefox. This would make the #navMain text taller, and perhaps sit behind the logo so it can't be clicked. Can't use IE7 on my computer.

You could use
Code:
#searchContent {padding: 0 2em !important;}
#searchContent input+input+input {
	margin-bottom: 6px;width: 100% !important;
	}
or simply assign a px or percent width like this, since the sidebox is not going to be changing width after you set it.
Code:
#searchContent input+input+input {
	margin-bottom: 6px;width: 90% !important;
	}