Well it sounds like there is some kind of conflict between the theme and the plugin. The ONLY way you find out the problem, is use the Web Console. Every browser has it’s own Console, you can find it from the Menu under Tools->Web Developer.
For Chrome, press Ctrl+Shift+I and reload the page.
For Firefox, press Ctrl+Shift+K and reload the page.
For IE, i don’t even use.
You should see every javascript error there and do changes to you code.