A user included to user group with "Internal" access type can not log in to Web-interface when HTTP auth was enabled.
He receives message: 'User name does not match with DB'.

I suppose the problem in CUser::login() function:

$dbAccess = DBfetch(DBselect(
'SELECT MAX(g.gui_access) AS gui_access'.
' FROM usrgrp g,users_groups ug'.
' WHERE ug.userid='.$userInfo['userid'].
' AND g.usrgrpid=ug.usrgrpid'
));

so MAX for gui_access is 1 = GROUP_GUI_ACCESS_INTERNAL.