Symantec NCO BHO taking extremely long to load in IE8

I installed Norton Internet Security 2011 a few weeks ago, upgrading my copy of NIS 2010.  Everything worked fine up until about 10 days ago, when my Internet Explorer suddenly stopped responding while trying to launch.  A little research revealed that the Symantec NCO BHO addon was the culprit, taking upwards of 3 minutes to load.  I just tried it again tonight, and it had a load time of 271.02 seconds.  I am running NIS version 18.1.0.37 and Internet Explorer 8.0.7600.16385.  I haven't made any other significant changes to my computer other than regular Windows Update.  Any suggestions?  I rely on my Norton Toolbar to manage my passwords, so having to disable it has been a tad inconvenient.