I have a forum where I successfully monetized through yieldmanager kind of ads (from Xtend media and DSNR media group, have tried both). However, my forum users one day complained that they found trojan warning on my site. After I removed all kind of yieldmanager ads, I never found any complain anymore. Well myself dont live in the US so ofc I've never seen those trojan ads by myself (since they dont display it to me). Then i switched to adbrite and it has been quite alright in the past 3 months before today 2 of my forum users complained they found extremely annoying ads (ad with sound!) and another one even complained they found a trojan ad through adbrite system. I wonder if you know any ad program that dont display trojans but pay per impression? I dont use adsense since it doesnt work well there and I also dont want to use gunggo (there was trojan report there as well...sigh). Im now using ad4game and before I used yieldmanager, I was also using ad4game. Ad4game never had any issue but my earning is small with them.