I know that annoys me they should know wheither you qualify for a survey right off the bat according to the profiles we filled out early on it makes you wonder how much attention is paid to our responses and why they send Surveys we may or may not qualify for it doesn't make any sense to Me.
Failing to qualify, (getting Dq'd from), any one survey depends on what may have 'gone wrong'. The possibilities include, (but are not restricted to); rushing through a survey, providing inconsistent answers, being disqualified under demographic criteria, not clearing "cookies" before taking a survey, having a survey's demographic-quota parameters fill while taking the survey, or not leaving the completed survey/"congratulations" page up for 5-10 minutes. Many of those things happened to most who've taken surveys before and they used to happen to me as well when learning the ropes. Evenso, sometimes 'glitch happens'.
Also, you might have a look at "CuppyCake's" post under "Offer Crediting Tips" in the Offers forum for more detailed advice.
http://www.fusioncash.net/forum.php?topic=7042.0