I'm not saying that creating back link in forum profile is bad. It does help to boost search ranking.
But I'm noticing more and more forums tightening up this loophole. Some forum owners even do something really stupid, for example timing the registration process. If an user complete a registration too fast, the forum will ban this user. That means genuine people who can type fast have to be real careful. This is just one of the silly things I just noticed.
So, for goodness sake, if you're using software, please do not run back link campaign too many times over a day. This is spamming.
First, you get yourself banned from many forums. Second, genuine forum users will get false positive ban. Third, people who do manual back link work will also get false positive ban.