Ptk crashes when USB audio devices are connected

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Start Ptk.
2. Connect USB sound card and wait for it to boot up.
3. Press Stop button.

What is the expected output? What do you see instead?
USB devices connected after program has been started should be ignored until 
program will be restarted. Now program just crashes.

What version of the product are you using? On what operating system?
2.5.4. on WinXP SP3

Please provide any additional information below.
Tested with Roland SonicCell.

Original issue reported on code.google.com by elbow...@gmail.com on 18 Jul 2011 at 6:33