Apache vu200* problem

[Quemeros]

I try to delete 2 sites, but i commet the error of delete 1 (don't wait for procces to finish) and delete another... then when i restart apache: error... the file (of 1 site) don't exist bla bla...

Later, i fix all thats missings, and then:
apache2: bad user name vu2006
failed!

Well, i fixed editing the files /etc/apache2/sites-enabled/ ...2006->2000 2007->2000... but, what change this users? what make this to system? what new problem can produce?

PD: Debbuger now returned: "250 as status code"