I have wondered about browser version. I just upgraded to IE 7.0 and had trouble getting offers to credit this week. OTX and SM surveys are crediting OK (when I can get one). I did notice that the Security setting on this 7.0 version of IE only goes down to Medium. I still have IE 6.0 at work and I can set that to 'Low' or 'Allow all cookies' (but I can't do offers from my work computer so no way to really compare which is crediting better).