Norton 360 seems to cause erratic and/or unresponsive mouse (cordless) and Keyboard (corded)

Hello.  For about the past 10 days, on an XP SP3 system (if I can do the work I am trying to do on my computer, I'll be able to (finally) afford a new computer...IF!), my Logitech LX6 cordless mouse has refused to cooperate.  Sometimes it's totally dead.  Other times it runs around haywire or slows to a jerky crawl.  Sometimes, noticeably when entering terms into a Chrome/Google Search, nothing happens when I type on the (corded) keyboard.  All updated to the max possible.  This cordless mouse works great on different computer.  I have uninstalled/reinstalled the MS generic mouse driver that's been in use for years.  I've uninstalled the MS, replaced with the correct Logitech driver.  I've uninstalled the cordless mouse itself.  Device Manager shows all's well...even hidden devices.

I've uninstalled/reinstalled Norton.  I've uninstalled/reinstalled Chrome.  I have repeated choice words in my head.  I have spent hours searching the 'Net.  I've found many references to the same problem and many include the word 'Norton'.  Before I uninstalled the Logitech driver, Norton was blocking the executable.  I've tried to add the mouse to the Trusted list and the Trusted Network Device list, but have had zero luck finding out what its IP or whatever address is.  I tried System Restore in Safe Mode to no avail.  I remember somewhere in my useless flurries of research that System Restore won't work unless I disable something or other in Norton.  I worked on this exclusively for two days now.  The mouse worked great until about 4 AM when I finally went to bed.  This morning...DEAD.

How can I go back to a couple of weeks ago in Norton Land when it all worked?  Help.  I have a huge project due on which my tiny business will depend for the next three years.  I'm using a corded mouse to try to eke by (no pun...), but it goes crazy too, just not as often.

HELP!