I just had the same issue. (Asus Transformer with android 3.2.1, PC with 64 bit Win7)
I then used the USB sync to make sure it was still set up properly (it was), unhooked the USB and ran the wireless sync again, and again got no response. (No error message, no nothing; like I didn't hit the command at all.)
I restarted CR for Windows and tried again and it worked fine. (Other than the fact that CR now doesn't want to recognize as valid a comic I've had on the laptop for over a month. -.-)
Not sure if it just needed a restart or something hung up or what.
ETA: Strange. I went to re-sync it wirelessly once I fixed that odd comic, and again got no response. Restarted CR and tried again, still no response. Hooked the transformer back up via USB, worked fine. Unhooked it, tried wireless, again no response. Waited a few minutes, tried wireless sync again, and it worked.