osCommerceITalia

Salve,
sto trasferendo il server da aruba a mondoservice.
ho finito di caricare il negozio via ftp/sql ma ricevo il seguente errore:

Warning: session_start(): Cannot send session cookie - headers already sent
by (output started at
/home/virtual/site92/fst/var/www/html/catalog/includes/application_top.php:4
) in
/home/virtual/site92/fst/var/www/html/catalog/includes/functions/sessions.ph
p on line 67

Warning: session_start(): Cannot send session cache limiter - headers
already sent (output started at
/home/virtual/site92/fst/var/www/html/catalog/includes/application_top.php:4
) in
/home/virtual/site92/fst/var/www/html/catalog/includes/functions/sessions.ph
p on line 67

Warning: Cannot modify header information - headers already sent by (output
started at
/home/virtual/site92/fst/var/www/html/catalog/includes/application_top.php:4
) in
/home/virtual/site92/fst/var/www/html/catalog/includes/functions/general.php
on line 29

Credo sia un problema di rilascio di cookie.

La sezione amministrazione funziona perfettamente.

Cosa può essere?