I built portaudio on rh75 in its normal 64 bit mode and when I run its test program pa_devs which lists the audio devices available, my usb sound card device is listed and my application that uses portaudio works fine. I built portaudio on rh75 in 32 bit form and when I run its test program pa_devs to list the devices, it doesn't list my usb sound card and so my application doesn't work. Why would a usb audio sound card be seen by a 64bit version of portaudio and not by a 32bit version  of portaudio? I assume it's using alsa under the hood so not sure why there would be any difference. Am I missing something on my RH75 linux install or ??? thanksMark Moreno