Hi Viart
 
Ive found quite a few differnet items in the default templates where there is invalid html markup.
 
I will make a note of these in posts as I find them here. Maybe others can do the same if they find any !?!?
 
First is
 
<b><u>{group_name}</b></u>
 
Which exists in various files if you do a search of the user template folder.