Dgethin-
From what I could find, this browser highjacker seems to be a PAIN to get
rid of. I found the following thread from a forum that discusses this very
issue. However, there are tools mentioned that you may not have, but could
get (ie. Highjack This). Highjack This can be a tricky tool to use, so be
careful. Below is the link to the forum and thread.
http://www.cybertechhelp.com/forums/showthread.php?t=100061
On a side note, I have found that sometimes you need to scan, reboot
immediately and scan again to truely get rid of some spyware/adware. Also,
Spybot has an option to scan at system startup. Have you tried that? This
option is in the Advanced Mode under Settings.
Lastly, Webroot puts out anti-spyware software, Spy Sweeper. I have found
this to be a good tool. Webroot used to offer a free trial, I'm not sure they
still do. You should check their site
www.webroot.com to see what they offer.
I haven't give you any definitive answers, sorry, but hope you find some
useful tools/info. from the above.
Good luck.