Not many people visit this forum any more so even though it is the correct forum for your version, If you don't get a good answer here in a few days, I would try a post in the X series forum where the majority hang out. It's allowed :}
I think the problem is Roland and Yamaha are direct competitors so they do this kinda stuff.
And as a side note, you really don't need to use your Yamaha for sounds, there are many great sounds available as soft synths. Try those first. Try the TTS-1 and other included synths and then look online for lots of low cost of free versions. The site "KVR" has many.