[PD] sound device positions change after reboot > Pd uses wrong soundcard

[tim]

Hi all,

Sometimes when I reboot, my soundcard seems to move up or down in the 
list of audio devices, causing Pd do start with the wrong one.
Also aconnect 16:0 128:0 fails because 16:0 is now 20:0...
It happens only now and then, so it's hard to test.
Last time it happened after I accidently turned off the computer (so a 
'dirty' reboot).
How can I make sure the position and name of my soundcard is consistent 
throughout several reboots ?
Or maybe dynamically adapt pd's startup options so that it will always 
use the right soundcard ?
This is on a desktop with ubuntustudio (7.04 feisty), an internal 
(VIA8237) soundcard and a PCI with breakout (Echo Layla3G), using alsa 
and alsa-midi, pd 0.39 (time to upgrade, I know...)
Any tips appreciated,
Tim