Marius,
My friend, no-one is attacking you here. You're not using the default theme, you're using a modified theme. I have the default theme and it doesn't have a picture of Micahel Jackson anywhere (that i can see at least).
Your issue was a CSS issue, because you had placed attached your CSS code to the wrong DIV for what you were wanting to achieve. It's nothing to do with BBpress, honestly mate, the issue was a CSS issue with CSS code that you added when you didn't know what you were doing. A CSS website would make a world of difference to you and your knowledge and ability to edit the themes. I'm not saying that to be cocky, i'm saying it to give you the tools to do these things yourself :)
When Im asking specifically for location of a code, in the DEFAULT THEME that comes with BBPress, the best place to ask is of course BBPress own forum
That's the key thing here mate, you were not asking that. You maybe thought you were, but the code that was wrong was in your CSS file, that you added - that's nothing to do with BBpress.
Given that it was your 2nd thread and your 4th attempt at asking for this solution in under 24 hours, I tried to help out - i gave you the simplest answer because your understanding of CSS was limited . You didn't understand the simple solutions presented, that's your web development knowledge, nothing to do BBpress.
No-one is paid to be here matey, we're all doing this because we want to help BBpress grow :) But that doesn't mean we have to be at your beck and call for real time support, nor does it mean that we have to answer basic web design/development questions that don't have anything to do with BBpress. I'm going to leave this here, clearly we have different opinions, and that's cool - but for your sake mate, not mine, learning a bit of Web Development skills will make your BBpress life alot easier.
Take care :)