You are using the old style tooltips not Joomla 3/Bootstrap popover tooltips. These old tooltips are more difficult to control and manage CSS interactions.

Can you update your template override for the module to use the new style tooltips? If you want me to do it please add the login details to the 'Site Details' tab below.

You are using the old style tooltips not Joomla 3/Bootstrap popover tooltips. These old tooltips are more difficult to control and manage CSS interactions.

Can you update your template override for the module to use the new style tooltips? If you want me to do it please add the login details to the 'Site Details' tab below.

My joomla version is 2.5

I'm afraid I can't figure out what CSS or Javascript on your site/template that is causing this positioning issue. You should consider seriously upgrading Joomla and JEvents to the latest versions since the versions you have are no longer supported.