I assumed you are using sdk1.1 for 20732 related work.
It seems that the image you have compiled is larger than 32 Kbytes.
Ok, the reason is this: if the your FW size is XX Kbytes, then the eeprom has to be at least 2XX Kbytes, During an upgrade, the eeprom size is divided into 2, the old FW is pushed into one half, while the other half accepts the new FW. If this is ok, only then the old fw is deleted. Such an approach is fail-safe.
OTA is not technically supported on TAG2 with SDK 1.x and the BCM20732, just the BCM20736/37 based products.
As you have discovered, one of the main problems on TAG2 is the onboard EEPROM is too small to support OTA.
This finally works.
I noticed that the hello_sensor sample application on my Win7 doesn't respond the notification from 20732.
So, what I do is to uninstall the WIDCOMM and Wiced Smart IDE. Reboot the system and install WIDCOMM and IDE again.
Then the magic is happen, notification of hello_sensor sample from tag board can be well show on Win7 application.
After that, I start the OTAFU test, and as our expect, it works.
What can say, magician Microsoft?
BTW, I have a question. Is there any system file install on Windows OS when install the WICED Smart IDE? If I do not run the installation and execute it once, would it be work fine?