Just got my website going a week ago and today I noticed that the error log fills up really fast by the same errors (see below). The row numbers for the first error are 178, 179, 180 and 183:

This second error has the row numbers from 199 to 225:

The third and last error is:

I've looked at the files and rows but there is nothing there to edit? Everything looks good and the same errors with all installed languages (swe, eng, nor, fin). If I clean the log out of errors and then refresh the page I get three pages filled with these errors right away and if refresh again there comes three more pages and so on, so these three errors floods the error log!

Please help me, really need to get rid of these errors! 

Take a closer look at the sticky posts, there you'll find the solution you're looking for... 

Maybe this hack still works:
http://www.joomlahacks.com/component/option,com_smf/Itemid,94/topic,2591.0

I haven't tried it myself yet, but this is something I really need, maybe I'll find the time tomorrow...

Ohh, sorry, my bad
I only read that last line...

Now everything works for new accounts but for the old members it still shows their realnames, but an easy way to fix it is to tell the users to go to their profile and update it by clicking on the "Update"-button in CB  (but they actually dont have to edit anything)... 

Now their Username is shown in the forums... 

Yes, I have that probelm too, I only want the username to be shown, not the real name. I've got the same setup...