Unable to have two browsers open after installing/uninstalling Yahoo Tool Bar?

As part of setting up my Yahoo account, I must have overlooked some option checkbox for installing the Yahoo Toolbar on my browser because after my account was setup, there it was. I did not want it on my browser, so I uninstalled it using the option on the toolbar. However, ever since I have been unable to have two browser windows open at the same time. If I have one open and try to launch a new one, it simply resets the open one to my home page (causing me to lose whatever I was viewing in it). 'The Reuse Windows..' checkbox under the Advanced Options does not appear to have an impact either way. I am using Internet Explorer Version 6 on Windows XP. How do I fix this so I can have as many browser windows open as I want (like before)?!? I hate it when companies/websites try to install stuff automatically on your system.