I don't know anything about this toolbar but I know, for example with some of the Norton and McAfee products, if there is an incomplete uninstall, sometimes the reinstall won't work properly.
With all your av stuff disabled, you could try the reinstall, reboot, try an uninstall from the program's uninstall menu, reboot, and reinstall again and see if that gets you any improvement.
Again, don't know how this would work in practice, but spybot has an ignore products setting, alexa stuff is under spybots, so in theory, once you had everything set up again, you should be able to use spybot and instruct it to ignore the alexa bar. Don't know how you might do that with Norton.
-------------------------------------
It's 10 O'Clock ( somewhere! ).
Are your registry and data backed up?