I first though it was addon issue, but no.

The problem is that I am hearing a metallish soft sound (there are 2-3 variations of it) as soon any mob around aggroes me. I tried to remove all addons and reset WTF folder, nothing helps. Neither can I find an option in interface to turn that aggro warning sound off. What should I do? :/

Just tried to disable a few, it's for sure not Omen or DBM.. :/

Bump.. this seriosly driving me crazy soon :(

i get those sounds too, i use cartog3, q helper, and x pearl, i can turn it down a bit so it dont do it so much with xperl it has a bottun under target toturn off aggro sound used by addons, but it's still there but only does it a few time after i did it, so that might work i dont know anything els though, i get a lot of weird prob with cartog3 since i DLed it, im not so sure what up. but yea take care peace

This seems to be issue with core wow files, not the addons. I see other people reporting same issue now.. damn, so annoying.. :(