We haven't been able to reproduce this problem at JRiver, but many people are reporting it so there must be some interaction going on that we need to replicate here. It could be Media Networking, auto import, NAS storage, an audio driver, a USB device, etc.
We need to start at the most vanilla Media Center setup and then add complexity until the dialog starts causing crashes. Start with auto-import turned off, Media Networking turned off, clear your library (back it up first), re-install the latest Media Center build, unplug any USB DAC devices, set your audio to play through the internal Mac speakers, re-boot your computer. Now try using the Options dialog and see if it causes a crash - hopefully not! Then turn on Media Networking, wait a bit and test the Options dialog. Then restore your library and test the dialog. Then plug in your USB devices and test.
Please report your results here. Thanks much for helping!