Arduino USB Host "Waiting for device..."

I've got the USB Host Shield for Arduino Pro Mini - https://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-for-arduino-pro-mini/

I soldered it to my Arduino Pro Mini 328 - 3.3V/8MHz - http://www.sparkfun.com/products/9220

When I run the board_qc sketch from the USB_Host_Shield_2.0 library https://github.com/felis/USB_Host_Shield_2.0, I get the following output regardless of what USB device I plug into the USB Host Shield:

Circuits At Home 2011
USB Host Shield Quality Control Routine
Reading REVISION register... Die revision 03
SPI long test. Transfers 1MB of data. Each dot is 64K................ SPI long test passed
GPIO test. Connect GPIN0 to GPOUT7, GPIN1 to GPOUT6, and so on
Test failed. Value written: 00 Value read: FF 
Press any key to continue...
GPIO test passed.
PLL test. 100 chip resets will be performed
Resetting oscillator
Reset number 0 Time to stabilize - 342 cycles
Reset number 1 Time to stabilize - 342 cycles
Reset number 2 Time to stabilize - 344 cycles
Reset number 3 Time to stabilize - 344 cycles
Reset number 4 Time to stabilize - 344 cycles
Reset number 5 Time to stabilize - 342 cycles
Reset number 6 Time to stabilize - 343 cycles
Reset number 7 Time to stabilize - 344 cycles
Reset number 8 Time to stabilize - 344 cycles
Reset number 9 Time to stabilize - 344 cycles
Reset number 10 Time to stabilize - 344 cycles
Reset number 11 Time to stabilize - 342 cycles
Reset number 12 Time to stabilize - 342 cycles
Reset number 13 Time to stabilize - 342 cycles
Reset number 14 Time to stabilize - 344 cycles
Reset number 15 Time to stabilize - 344 cycles
Reset number 16 Time to stabilize - 344 cycles
Reset number 17 Time to stabilize - 344 cycles
Reset number 18 Time to stabilize - 344 cycles
Reset number 19 Time to stabilize - 344 cycles
Reset number 20 Time to stabilize - 342 cycles
Reset number 21 Time to stabilize - 342 cycles
Reset number 22 Time to stabilize - 342 cycles
Reset number 23 Time to stabilize - 344 cycles
Reset number 24 Time to stabilize - 344 cycles
Reset number 25 Time to stabilize - 344 cycles
Reset number 26 Time to stabilize - 344 cycles
Reset number 27 Time to stabilize - 344 cycles
Reset number 28 Time to stabilize - 344 cycles
Reset number 29 Time to stabilize - 342 cycles
Reset number 30 Time to stabilize - 342 cycles
Reset number 31 Time to stabilize - 344 cycles
Reset number 32 Time to stabilize - 344 cycles
Reset number 33 Time to stabilize - 344 cycles
Reset number 34 Time to stabilize - 344 cycles
Reset number 35 Time to stabilize - 344 cycles
Reset number 36 Time to stabilize - 344 cycles
Reset number 37 Time to stabilize - 344 cycles
Reset number 38 Time to stabilize - 342 cycles
Reset number 39 Time to stabilize - 343 cycles
Reset number 40 Time to stabilize - 343 cycles
Reset number 41 Time to stabilize - 344 cycles
Reset number 42 Time to stabilize - 344 cycles
Reset number 43 Time to stabilize - 344 cycles
Reset number 44 Time to stabilize - 344 cycles
Reset number 45 Time to stabilize - 344 cycles
Reset number 46 Time to stabilize - 344 cycles
Reset number 47 Time to stabilize - 342 cycles
Reset number 48 Time to stabilize - 342 cycles
Reset number 49 Time to stabilize - 344 cycles
Reset number 50 Time to stabilize - 344 cycles
Reset number 51 Time to stabilize - 344 cycles
Reset number 52 Time to stabilize - 344 cycles
Reset number 53 Time to stabilize - 344 cycles
Reset number 54 Time to stabilize - 344 cycles
Reset number 55 Time to stabilize - 344 cycles
Reset number 56 Time to stabilize - 342 cycles
Reset number 57 Time to stabilize - 342 cycles
Reset number 58 Time to stabilize - 344 cycles
Reset number 59 Time to stabilize - 344 cycles
Reset number 60 Time to stabilize - 344 cycles
Reset number 61 Time to stabilize - 344 cycles
Reset number 62 Time to stabilize - 344 cycles
Reset number 63 Time to stabilize - 344 cycles
Reset number 64 Time to stabilize - 344 cycles
Reset number 65 Time to stabilize - 342 cycles
Reset number 66 Time to stabilize - 342 cycles
Reset number 67 Time to stabilize - 344 cycles
Reset number 68 Time to stabilize - 344 cycles
Reset number 69 Time to stabilize - 344 cycles
Reset number 70 Time to stabilize - 344 cycles
Reset number 71 Time to stabilize - 344 cycles
Reset number 72 Time to stabilize - 344 cycles
Reset number 73 Time to stabilize - 344 cycles
Reset number 74 Time to stabilize - 342 cycles
Reset number 75 Time to stabilize - 342 cycles
Reset number 76 Time to stabilize - 344 cycles
Reset number 77 Time to stabilize - 344 cycles
Reset number 78 Time to stabilize - 344 cycles
Reset number 79 Time to stabilize - 344 cycles
Reset number 80 Time to stabilize - 344 cycles
Reset number 81 Time to stabilize - 344 cycles
Reset number 82 Time to stabilize - 344 cycles
Reset number 83 Time to stabilize - 342 cycles
Reset number 84 Time to stabilize - 342 cycles
Reset number 85 Time to stabilize - 344 cycles
Reset number 86 Time to stabilize - 344 cycles
Reset number 87 Time to stabilize - 344 cycles
Reset number 88 Time to stabilize - 344 cycles
Reset number 89 Time to stabilize - 344 cycles
Reset number 90 Time to stabilize - 344 cycles
Reset number 91 Time to stabilize - 344 cycles
Reset number 92 Time to stabilize - 342 cycles
Reset number 93 Time to stabilize - 342 cycles
Reset number 94 Time to stabilize - 344 cycles
Reset number 95 Time to stabilize - 344 cycles
Reset number 96 Time to stabilize - 344 cycles
Reset number 97 Time to stabilize - 344 cycles
Reset number 98 Time to stabilize - 344 cycles
Reset number 99 Time to stabilize - 344 cycles
Reset number 100 Time to stabilize - 344 cycles
Checking USB device communication.

Waiting for device ...
Waiting for device ...
[this repeats forever...]

Summary: The Host Shield just gets stuck in a loop saying "Waiting for device ..." and never actually connects to the USB device that is plugged in.

Does anyone have any recommendations on how I can debug this to figure out what is wrong? Thanks!

I found the problem with my setup. The USB Host Mini requires 3.3V, and I was providing 5V to it via my USB BUB II programmer. When I modified the USB BUB II to give my Arduino Pro Mini and USB Host Mini 3.3V, the shield started working perfectly :-)