Piping multiple lines of text via ssh

hello,

i have set my own app as the shell of a user on a remote host. My app
reads from stdin, and prints output to stdout.

If I do:
ssh user@remotehost.com

and manually type multiple lines of text,the app works as expected (i.e. it
processess each line, and outputs the result)

However, if I do this:

ssh -T user@remotehost.com < file.txt

my tool only processes the first line, and then quits.

any clues?

thx, - m