For some time now Google Analytics has not been tracking the traffic to Grandma Cybersalt's piano teaching web page. I was positive I had everything set up properly, even triple-checking the exact same steps that worked on my other sites. So today I determined to take the time to site down and find out whatever strange thing was going on.
Reading this prompted me to wonder if a Joomla plugin I was using to compress scripts (to decrease page load times) might be the cause of the problem. I viewed the list of plugins installed on my wife's site, sorting them in descending order of ID# so that the ones I have installed appeared at the top of the list ahead of basic Joomla plugins which I knew were not the problem. Lo and behold, there it was - a plugin named "JCH Optimize". I had experimented with it a year ago to see if it could help my pages load faster. As soon as I unpublished that plugin, Google Analytics began tracking my visits to the site.
However, with my curiosity satisfied, I uninstalled JCH Optimize and installed RokBooster, my favorite plugin that cuts page load speeds. With Rokbooster installed and published, Google Analytics kept working and my wife's site's Page Speeds and YSlow scores jumped beyond JCH Optimize could provide (as tested at www.gtmetrix.com.)