Hi
The plugin tries to match a category title to the text you enter. It is designed to be case insensitive and only require a snippet. New or inexperienced users were having problems related to category title errors including non-existant categories, multiple-categories and categories that contained the article in which they had called the plugin (this final error was crashing the server because of an infinite loop).
To make things a little easier, the plugin should now spot errors and produce a warning. The category title is also more relaxed and will find ANY content categories that match you text snippet. You could look at the ability to match more than one category as a feature... To match one category you must choose a title that is unique - in your example you would change your syntax for the plugin for search for "services". This isn't really a bug in my opinion...
The second problem you've mentioned is that the articles are all open. This is a javascript error that is something conflicting on your site. See
this thread