All you have to do is add one line of code to your template.
1.) Login to your Joomla 2.5 Administration Panel.
2.) Go to: Extensions/Template Manager
3.) Click on Templates
4.) Click on the template you are using for your website
5.) Click on 'Edit main page template'
6.) Find the following line of code:
<jdoc:include type="head" />
7.) and add the following line:
<meta name="SKYPE_TOOLBAR" content="SKYPE_TOOLBAR_PARSER_COMPATIBLE" />
8.) both lines will look like:
<jdoc:include type="head" />
<meta name="SKYPE_TOOLBAR" content="SKYPE_TOOLBAR_PARSER_COMPATIBLE" />
9.) DONE!!!