Don't know the permanent fix, but as a temporary measure, open up your HOSTS file (c:\winnt\system32\drivers\etc\hosts in NT/2k/XP or c:\windows\hosts in Win9x) and add this line:
127.0.0.1 c5429.wabu.com
That should at least keep that site from loading up. Then look for an ad cleaner of some time, many are mentioned in the thread linked above.