[treszoks]

Assuming the linebreaks were added to the db:

In member.php find this in the "getinfo" action segment (should be around line 1200):

$profilefield[value]=$userinfo[$profilefieldname];

Change it to this:

if ($profilefieldname == "fieldX") //where X is the field number
{
$profilefield[value]=nl2br($userinfo[$profilefieldname]);
}
else
{
$profilefield[value]=$userinfo[$profilefieldname];
}