Once again I must say I am disappointed with WD, not only we have to wait several months for the new firmware to be released, but they have not added support for Wireless USB Sticks that are on the market. Very disappointing...
You have to remember that the WD box is not a PC. With a PC, you go to the internet, find the right driver, install it, and you are ready to go. With the WD box there is no way that you can install drivers. That means that the WD firmware has to contain the drivers for all of the adapters that they support. It would be impossible to have drivers built in for every adapter that is on the market. That is why WD provides us with a list of supported adapters. If you get an adapter that is not on the list, it might not ever be supported.
Add to this the fact that the adapter manufacturers have a bad habit of changing the chipsets inside the adapters when they change the revision level, and you can see how hard it would be for WD to support everything. Why don't you just use one that is on the approved list?