Simulating IrDa devices

Hi,

I used to have a setup, where I used irattach on two linked pseudo 
terminals (like a virtual nullmodem cable) to simulate an IrDA device. 
To make it work I had a "server" simulator application that listens on 
an IrDA socket and serves some data like my real device would do. Then a 
"client" application would connect to an IrDA socket and communicate 
with the server application.

The pair of pseudo terminals were created with socat:

$socat PTY,raw,echo=0,link=/tmp/ttyS0 PTY,raw,echo=0,link=/tmp/ttyS1

And then I would run irattach on each of the pseudo terminals

$irattach `readlink /tmp/ttyS0`
$irattach `readlink /tmp/ttyS1`

Note that irattach doesn't seem to like the symbolic links, hence the 
readlink.

This used to work fine some time ago, but after a couple of (ubuntu) 
upgrades it doesn't work anymore. As soon as I start up the client 
application, my entire system locks up.

Does anyone knows how to make this work again?

Thanks,

Jef