Auto Voltage Regulator + Computer Power Supply Inquiry?

I have a generic AVR that I've been using for almost a year. I've been using it with a 500W Power Supply. It only has 3 slots of 220V. It works fine until last April 2011. I just bought a new computer and this time with a 700W PSU. Just a while ago, we're smelling a sulphur-like burnt out stink. We're getting nervous because we're trying to find where the smell is coming from. Its not in my computer because its still running fine. Until we've discovered it was coming from the AVR. I'ts working fine but the smell is really strong like it's burning. We've turned off the computer immediately. What may be the cause of this? is it my 700W PSU that cannot be handled by my generic AVR? I just borrowed a somewhat heavy duty AVR with a voltage indicator.. It's large and heavy. So I believe this is a heavy duty AVR. It states the 500VA in the unit. Will this help or will burnt out like my old AVR? Pls help. Thank you!