I've been using Fbackup a few years. Thankfully, I've never had to call upon it to restore. Two things:
1) It seems over time that when once the program would complete with no warnings, over time, the number of warnings has continued to increase, plateau, increase, plateau, etc. Having had about a year with 28 warnings, it recently posts 32 warnings. I've done nothing different to create this happening. I also have no idea what the warnings mean.
2) Some mornings I find that the program says it couldn't find my scheduled job. Sometimes it does.