You mentioned keeping up on the McAfee virus checking.
Do you also use an Uninstaller to clean up your hard drive? Perhaps the one called Cybermedia Uninstaller?
I ask because about two years ago, I was being a good girl and used that program to hunt down files left over after using Windows Uninstall. I accidentally deleted a file that Cybermedia SAID wasn't needed anymore.
That messed up the genealogy program I was using at the time, Roots 4 or 5 or Visual. I don't recall how I found out that the Uninstaller made that error. I wrote down the name of the file to NOT uninstall. Of course, I can't find where I wrote that down. If you didn't use a program that does 'uninstall cleanup' than that is not the source of your problem.
I reviewed most of your messages and don't see which version of UFTree you are using nor do I see which version of Windows your are using, nor how big is your hard drive and RAM, nor how much free space you have on the hard drive. Do the 'error' messages that occasionally pop up in other programs than UFTree occur when you have many programs open? or when you have not closed your internet programs? Perhaps the above information will help us figure out what is going on.