MPD automation trouble

[Paul]

Hello, All.

I use MPD under FreeBSD 4.7.
Now i needed to automate management of the MPD and i find out strange behavior of MPD (3.13):
One my program (myserver) transmits some set of commands for MPD via stdout, which is redirected
to MPD's stdin by shell:
command line: "# myserver | mpd"
One or two commands from this set are executed by mpd immediately, but other commands from
set hang somewhere until myserver sends to MPD another command's set, after that previouse
commands are successfully executed by MPD and new commands hang somewhere again.
When i use command like "# myserver | cat", full set of commands is printed to console.
I want to understand why this happens and where commands hang.
Help me to solve the this problem, please.

Paul