Problems with Attachment

Im having problems with Attachment files with RT, we can send them with
the new ticket, and we can see the link to the Attachment, but if I
click in the link, Apache gives an error of page not found in the
server, I look in the table Attachment into MySQL and the file attached
is there, more, if the file attached is a text file we can see it paste
in the text of ticket.

Can someone help me?

Antonio Sanchez
a.sanchez@ciemat.es