Tool tips only displays once

Hi I am trying to using tool tips to display definitions of key terms used in a survey. The tool tips work well with custom css and java script code I obtained from the users forum for two questions. I am however experiencing challenges with some questions as the tool tips display only once and don't appear again once I click or move the mouse away from the key word. I also notice the dotted line under the key words disappear as well when the mouse pointer is moved away from the key words. I am using the exact same code for all the questions and can not figure out why for the first two questions the code works well and not for those that follow.
Any help with this is greatly appreciated.

Thanks,

Rmusoke