I bedroom converted to office space. One wall is a closet. Each of the other three walls has an electrical outlet. One of those is controled by a light switch.

The outlet controled by the light switch has a chain of surge protectors around the walls with six lamps plugged in at various points along the chain. Nothing else.

One outlet has a portable 9000btu airconditioner. Nothing else.

The last outlet: The top plug has a UPS with my computer, three monitors and about 5 computer add ons such as a usb hub, speakers, DSL, ect.

The bottom plug has a surge protector with a stereo, TV, VCR.

PROBLEM\QUESTION: The outlet with the UPS plugged into it is making a ddzdz noise. Ocassionally, I can see sparks on the inside of the outlet housing (not the outlet). Don't worry;) I unplugged everything in the room.

Could it be a bad outlet?
Can I replace this outlet and fix the problem? It has been working fine for about a year.

Do I have too much stuff plugged into the UPS?

Also, why didn't the curciutbreaker blow?

Thanks in advance for any suggestion, help, or insites,