I have adium now for a while. I recently updated it to the last version. But what do i see, before i had to enter my password to start adium (to log on). But now they don't ask that no more. The program or automaticly log on or you have to choose your status and he will log on. This means that everyone who is on my computer can open adium and use it. I don't get that...! That's not safe... And nowhere i can find an option to make that work...
Why are other people all over your computer? That may be the first thing to look at. However, in the account preferences if you do not enter a password, it will ask for your password to connect every time. There is also a checkbox on the same screen in account preferences that says "Connect when Adium opens". Uncheck that if you do not want adium to automatically connect.
Are you using a localization? It seems we have found a bug where the prompt is not showing up in non-english languages. Try switching to english and see if it shows up.