My Norton keeps advising me it has detected an intrusion called http lop toolbar.  I understand it is some sort of adware and have used Spybot and nolop (which detected a problem and said it deleted it) and have my NOrton up to date, but Norton still tells me it is there.

Thanks for the input.  When I rebooted the second time after the nolop program found something, it seems to have fixed it.

You may have already looked at this page.
http://www.symantec.com/security_response/writeup.jsp?docid=2003-092919-5421-99
If you look at the remove tab, that page indicates you need to delete some registry entries to completely remove it.