Just to be more clear, they worked with "light fingertip pressure" and now they are "unresponsive". So, are they completely unresponsive or are they just not "light fingertip pressure" anymore?
If they don't respond, as when they first did when you purchased the Ultrabook with "light fingertip pressure" and they respond late or it lags. Perhaps the problem is not hardware but junk that is slowing your computer down.
If they are completely "unresponsive" or damaged to where a replacement is required than you will need to waste a pretty penny depending on your budget. And yes, it is kind of a major fix.
I hate to be anal about this, but since I am unsure weather your problem is hardware or software I can give you no further advice.
Culer fins ala mort!