I have never understood the fuss over this. I have left many Objectivist boards because of silly infighting and 'I am more Objectivist than thou' thinking. People can call themselves whatever the hell they like. Their thoughts speak for themselves. Like pro-choice Catholics, there is no debate on whether or not someone is an Objectivist or not.
A thing on disagreement- Objectivists can, and should, disagree. It's healthy. It's fun. We make error judgements and errors of knowledge like anyone else. The only way to discover our errors is through critical thought and debate. I disagree with Rand on her views of the nature of women and on homosexuality (for example).