Segfaults in libusb / rtlsdr_close

I'm seeing crashes in libusb when calling rtlsdr_close, typically like this: cancel_async cancel_async done pthread_join read_async returned lock mutex signal cond unlock mutex thread finishing pthread_join done closing device rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 r82xx_write: i2c wr failed=-1 reg=06 len=1 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 rtlsdr_write_reg failed with -1 [Thread 0xb6cd5470 (LWP 3232) exited] Program received signal SIGSEGV, Segmentation fault. 0xb6ef6c28 in libusb_submit_transfer () from /lib/arm-linux-gnueabihf/libusb-1.0.so.0 (gdb) bt #0 0xb6ef6c28 in libusb_submit_transfer () from /lib/arm-linux-gnueabihf/libusb-1.0.so.0 #1 0xb6ef83cc in libusb_control_transfer () from /lib/arm-linux-gnueabihf/libusb-1.0.so.0 #2 0xb6f0bfa4 in ?? () from /usr/lib/arm-linux-gnueabihf/librtlsdr.so.0 Cannot access memory at address 0x2ebd8a8 (Yeah, the stack's not very useful, but the eventual caller is definitely rtlsdr_close) There's a thread blocked in rtlsdr_read_async(), but I call rtlsdr_cancel_async() and wait for rtlsdr_read_async() to return (and the thread to terminate) before trying to close the device. This is with the current github version of librtlsdr on a Raspberry Pi with libusb 1.0.11 from the standard Raspbian package (2:1.0.11-1) Anyone seen this before? Oliver