sftp expect timeout problem

hello All,

I am doing SFTP using expect. We just change our server from sun solaris 8 to sun solaris 10.
The script was working good on sun solaris 8.
But it is giving problem on 10. from shell, SFTP is working fine.Please help me.
What can be the problem.

LIB_sftp_get()
{
   _remote_file="$1"
   _local_file="$2"
   if [ -z "${_remote_file}" ] ; then
      LIB_log_mail_exit "LIB_sftp_put(): no remote file"
   fi

   if [ -z "${_local_file}" ] ; then
      _local_file="${_remote_file}"
   fi

TMP_SFTP_ID="xx.xx.x.x"
TMP_SFTP_USERNAME="xxx"
TMP_SFTP_PASSWORD="xxxxx"
TMP_SFTP_REMOTE_DIR="xxxxxx"
TMP_SFTP_LOCAL_DIR="XXXXXX"
TMP_SFTP_TIMEOUT=-1


expect <<EOF
   set timeout $TMP_SFTP_TIMEOUT
   spawn  sftp $TMP_SFTP_USERNAME@$TMP_SFTP_ID
   expect "password:"
   send "$TMP_SFTP_PASSWORD\r"
   expect "sftp> "
   send "lcd $TMP_SFTP_LOCAL_DIR \r"
   expect "sftp> "
   send "cd $TMP_SFTP_REMOTE_DIR \r"
   expect "sftp> "
   send "get ${_remote_file} ${_local_file} \r"
   expect "sftp> "
   send "bye \r"
EOF

   if [ $? -ne 0 ] ; then
      echo "Failed: LIB_sftp_get()${_remote_file} ${_local_file}"
   fi

   return 0
}

Many thanks in advance.

Regards
Abhishek Kumar