Recently my browser started to repeatedly lose the ability to support multiple tabs. In Internet Explorer 8, I click on the drop-down menu arrow on the right side of the Command Bar's Home button, select Add or Change Home Page from that drop-down menu, and then select "Use the current tab set as your home page" in the Add or Change Home Page dialog box. Then I launch another instance of the browser and close the original one. Then I've got multiple tabs. Sometimes they'll still be there the next time I boot up, but after a couple times, they're gone again. I have an installation of Windows that’s only a few weeks old (so I doubt any files are corrupted), and all my antivirus and antimalware software tells me I’m as clean as a whistle. How do I fix this?