Post Voting Plugin with Allow daily voting

Hello, we purchased Post Voting Plugin with Allow daily voting, it seems that "allow daily voting" is not working properly. This plugin is supposed to allow users to vote once in 24 hours, but is not. We were received plenty of complaints from our users, then we tested plugin as well, and after 30 hours still we can't vote for specific article.
How can we fix that issue?

Thank you

Jurica Mateši?, web design
Spotstudio d.o.o.
Katan?i?eva 3
10000 Zagreb, Croatia
tel.: + 385 01/4922-560, 888 67 33
fax: + 385 01/4810-537