Hi everyone - this was a solution posed earlier in the thread that I found to be successful. I listen to iTunes for several hours a day at work, and the problem was widespread and has basically disappeared. So please consider giving this a try. (and I can't take credit for this, someone else worked with Apple on this).
I'm on a windows so some of this may vary for ya mac users out there.
First close down itunes
Next go to your itunes music library.
(Turn on show file extensions)
Move iTunes Music Library.xml to your desktop
Move iTunes Library .itl to your trash/recycling bin
Now open Itunes
Go to File -> Library -> Import playlist and then select the iTunes Music Library.xml (which was on the desktop)
Now depending on your library size/speed of computer this can take a few moments
Assuming this works for you, and if you have other products (iPhone, iPad) that you use, you need to delete all of the music files from those devices, and then reload the music onto them. Otherwise, songs on those devices that had issues won't be fixed.
A few other thoughts in case you have questions. I didn't find this to be a Match issue (I wasn't using Match, nor were many others who had this issue), and it also seemed that although the songs were ending prematurely, we didn't find that it was corrupt files, it was more of an issue with iTunes.
Hope this works for you.