new large dl for xbuntu 14.04 has mystery mouse response

What was the file you downloaded? Was it in regular updates?

I have tried a few "fixes" and thought I should give more info. First the info -- This is Xubuntu 14.04 -- running on an HP laptop bought new last November. It had been working quite well before this "update" install that showed in the Software Updater. There was no name on the install other than Ubuntu. Surprised to see such a complex and very large download.
     Now for the observations. Sometimes after a reboot or a system shutdown all is well with the cursor. I am able to guess where the cursor is by moving the mouse and observing how it affects the screen messages and then use the shutdown procedure. I have poor luck with the "hibernate" mode. I found that is not usable. Start up does not cure from that mode.
    I noticed I had also a problem with erratic cursor, so I installed Touchpad Indicator. That works well when typing, but no help with the hidden cursor. I have consistent good luck by shutting down the computer and booting when it is time to use. Just a bit time consuming.
     So , , , I am hoping someone has an answer for this irritating mess. Perhaps there is another magic utility I have not found to keep the cursor alive' I have written these several paragraphs with no hitches. Hopefully, it will not require a fresh install. I doo use this computer often. Thanks -- Jack

Today, I tried installing an update in the software updater, and the system locked up part way through. It was working to install the line "3.19.0.68-50 over 3.19.0.66.48" at lock-up. Had to sht it down by powering off. Restart seemed OK as I am writing this,
      So . . . that is the news of the day. Maybe more bugs than I can count. Hope this helps.
I also found a description of most of these problems in bug # 1568604. Jack

Well . . . Looks as though this bug has been around for a year. Sorry to take up the space. Will check back later.
              Jack

Okay Folks, I finally fixed the problems. Too complex for this skinny little 82 year-old mind to explain. I will simply give you the broad scope of facts. This a real kluge box to begin with. Last Fall I purchased a new HP laptop with Windows 10 and immediately removed the MS operating system leaving me with a decent piece of hardware, then installed the Xubuntu 14.04. Seemed like a logical combination. Did what I wanted. Great experience!
    It was going well until the stated problem surfaced. A few things helped but it was a never ending struggle. So . . . I gritted my teeth and installed the available update from the Software Updater, Xubuntu 16.04 (after, taking the precaution to copy the important data to a back-up machine.) I do keep a lot of files and there are some that are hard to replace.
    The process appeared as though the system would grind to a halt and fail. After about four hours it finished the process and with a few nudges from this impatient operator it said it was time to reboot. Whew! Best system update ever. Everything was intact. Even a few patches that were keeping the (previously) cursor from interfering. What I am saying is the whole thing works better than ever. Really ! ! !
    The problem of the missing and/or wandering cursor is fixed. I have to stamp this as Problem Solved.

    Thank you for the support .. Hope you can draw conclusions from this and advise others.

     Jack