I've got a couple of my AC adaptors fail at different times during what I assume were power spikes, while being connected to my UPS. It's a pretty old APC 500 which I use only to back up my router and external hard drive. Though it's couple of years old and I havent changed the battery ever it still gives me around 5 minutes of power so I can shut down everything properly.
First when my router's AC failed I thought it was just faulty, then later when hard drive's AC failed also, I started to think that the problem is the UPS as other AC that were connected directly to the grid stayed fine.
So the question is: should I replace my UPS with a newer one, or is the whole idea of connecting appliances AC adapters to UPS just wrong and it's only for PC ACs.