I had the test that if piwik could record two different campaigns A and B when I visit the site through campaign A then B successively in very short interval. (about 10 seconds, I know it is much more less than 30 minutes, the session time)
(with url parameter; pk_campaign=A&pk_keyword=a
pk_campaign=B&pk_keyword=b)

Piwik recorded my two visits but did not capture campaign B, the second campaign.
Only campaign A is recorded. However I want to track every campaign although there was very short term between the visits.

So I had some googling,
then, I changed the variable "create_new_visit_when_campaign_changes" to 1 in config.ini.php

but It doesn't work.

How can I figure it out? Please help!