My usb device works for a while then quits.

[David Csercsics]

You wrote:
>I have an alva connected bia usb to my computer but after a few minutes of
>activity, it quits.  Root can access the device but a normal user can't.
>Someone suggested I mount the usb devfs as read/write.  The question is where is
>hotplug/libusb mounting the usb system and what is the best way to re-mount it?
try fixing the usbfs line in fstab like this:

usbdevfs /proc/bus/usb usbdevfs mode=666,defaults 0 0
That will force the file system to be mounted with read/write access for everybody.