AVG Tuneup zeroing Firefox Bookmarks

I go to AVG Tuneup.  Check Speedup, Programs for Firefox.  FF shows as running (and using resources).  I run Maintenance.  After all the cleanup I reopen Firefox.  When I do, some of my bookmarks no longer work.  Not all of them, just some of them.  If I right click on the non-working bookmarks and select Properties, the only things I see are "Cancel" and "Save."  It seems as if Tuneup is wiping the location of certain bookmarks.  This has been happening on and off for better than a month now.

Hi Jon,

We're glad to look into this & help you.
In order to further investigate on this & make this  process easier, we'd suggest you to take advantage of our additional support, by following the steps in the email that has been sent to you. 
Thank you for your understanding in advance!

Hi Jon,

We're glad to look into this & help you.
In order to further investigate on this & make this  process easier, we'd suggest you to take advantage of our additional support, by following the steps in the email that has been sent to you. 
Thank you for your understanding in advance!