I have had problems with DNS Unlocker for about 8 months now.
I tried all available tools and solutions out there (including the ones presented in this thread).
They were unsuccessful on the long term (even if I was clean for a few hours/days/weeks).
DNS Unlocker works via a Javascript in your browser. Blocking Javascript in your browser would get rid of the problem, but you can't use the interenet with Javascript blocked these days.
Another method is to block the websites that distribute this script using your hosts file.
A guide is available here: http://winhelp2002.mvps.org/hosts.htm
However, don't use the entire list from there, if you are not confortable with that.
Here is the list I used, this is enough to block DNS Unlocker todat. They might change the servers serving the script tomorrow, but you can always update the list. Please report back if this worked. Just add the following lines to your hosts file using Notepad.
You can find the servers yourself by pressing F12 in Chrome on an infected page and looking at the Network tab, then JS tab, and looking for DNSUnlocker entries. This is how I came up with this list.
EDIT: before reporting your results with this method, please flush your DNS and clear browser data (cookies ans such). You probably know how to clear your cookies. To flush your DNS, open an elevated command prompt and type ipconfig /flushdns
0.0.0.0 ads.ad4game.com
0.0.0.0 bdv.bidvertiser.com
0.0.0.0 scsdev
0.0.0.0 ib.adnxs.com
0.0.0.0 segment-pixel.invitemedia.com
0.0.0.0 cas.criteo.com
0.0.0.0 tags.bluekai.com
0.0.0.0 ld2.criteo.com
0.0.0.0 pixel.invitemedia.com
0.0.0.0 pix04.revsci.net
0.0.0.0 vt.adition.com
0.0.0.0 vube.com
0.0.0.0 lp.sharelive.net
0.0.0.0 www.888poker.com
0.0.0.0 888poker.com
0.0.0.0 www.bet365.com
0.0.0.0 bet365.com
0.0.0.0 kovla.com
0.0.0.0 888casino.com
0.0.0.0 www.888casino.com
0.0.0.0 10990-29575966.ampxchange.com
0.0.0.0 www.safesidetab.com
0.0.0.0 www.tradeexchange.com
0.0.0.0 yxo.warmportrait.com
0.0.0.0 m73.dnsqa.me
0.0.0.0 comparinggenie.com
0.0.0.0 www.comparinggenie.com
0.0.0.0 www.dnsunlocker.com
0.0.0.0 dnsunlocker.com
0.0.0.0 visadd.com
0.0.0.0 a.visadd.com
0.0.0.0 cdn.visadd.com
0.0.0.0 tag.imonomy.com
0.0.0.0 nps.pastaleads.com
0.0.0.0 pstatic.eshopcomp.com
0.0.0.0 w3i.co
0.0.0.0 istatic.eshopcomp.com
0.0.0.0 cdncache-a.akamaihd.net
0.0.0.0 asrvvv-a.akamaihd.net
0.0.0.0 srv.imonomy.com
0.0.0.0 a.softpeaches.com
0.0.0.0 jem.recombinantsunengaged.com
0.0.0.0 kdv.decipheringwarns.com