Wireless Adapters

The reasons could be numerous really. The clavinova has to have software writen into the memory to interface with that specific wireless card. The easy answer is that they simply can't write in drivers to every possible wireless card of every brand. This is especially true when you are dealing with wireless cards that we're produced after the piano is built. The drivers simply didn't exist when the manufacturer made the driver support for the piano.

Wireless cards aren't plug and plug even on a computer, they need drivers, and this goes without saying on a device like a piano. So without the ability to upload and install software/drivers onto your piano you've got to deal with the driver support they built into that model.

A more technical answer to the question would be the difference in internal chipsets these wireless cards have can make a huge difference. Wireless networking technology is a HUGE market right now and the companies that supply them change the internals literally almost monthly. This is based off the cost of the parts needed to built the unit fluctuating and the features needed to be built into the device. For example a linksys router with the same model number wrt54g has over 8 different versions with different chipsets in each one.
Some budget chipsets aren't as good as others. They don't get as good signal, and it's not easy / possible to make a robust driver selection for them. This can lead to the problem you're encountering. You have 2 wireless cards that on the outside look like any other wireless card, but on the inside may not have a chipset thats as good as some others in terms of hardware.

Manufacturers generally make these changes in chipsets based off the bottle line price. If they can purchase a similar chipset from a company for cheaper they are going to do it to make more profit. Most networking companies to not list the differences in chipsets at all. It's pretty much up to the enthusiast crowd to take them apart and find out who made the chips, what operating system they run, and what specs they have. This information can sometimes be found on the internet with the more popular hardware, but sometimes the obscure or less special stuff can get ignored. In the end there isn't really a sure fireway to find out the specs of every piece of wireless hardware on the market.

I hope this has explained your question in detail. If I've helped you please don't forget to rate me.

Peter