Hola chavos... por el problema que tengo es el mismo...
  
[Session] 
session.save_handler = files 
session.save_path = "C:\httpd\xampp\tmp" 
; Whether to use cookies.
session.use_cookies = 1 
; This option enables administrators to make their users invulnerable to
; attacks which involve passing session ids in URLs; defaults to 0.
; session.use_only_cookies = 1 
; Name of the session (used as cookie name).
session.name = PHPSESSID 
; Initialize session on request startup.
session.auto_start = 0 
; Lifetime in seconds of cookie or, if 0, until browser is restarted.
session.cookie_lifetime = 0 
; The path for which the cookie is valid.
session.cookie_path = "C:\httpd\xampp\tmp" 
; The domain for which the cookie is valid.
session.cookie_domain = C:\httpd\xampp\tmp 
ya reinicie y me sigue marcando  
Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at C:\httpd\xampp\htdocs\computo\insert.php:3) in C:\httpd\xampp\htdocs\computo\insert.php on line 6  
me podem ayudar... esto  me lo marca con el XAMPP 

 ... pero con el appserv nunca me lo marca...