Bc2000 (for the BCF2000 & BCR2000)

My wife and I just got a BCN44 last week and had the same problem. Luckily it only occurred on a keyboard we were borrowing temporarily, and was completely fixed by switching to another keyboard. 

We got The BCN44 to add some controls to our VSTi instruments when using a keyboard without assignable encoders or buttons. Because our USB interface has only one MIDI input, we are using MIDI merge on the BCN44. 

When I plugged the first keyboard (Yamaha P-95) and BCN44 in together (keyboard out -> BCN44 in, BCN44 out -> USB MIDI interface in) the keyboard did not function properly at all. Any note pressed would sustain indefinitely. For a few seconds after a note was played no other keys would work. When another note was played after this delay the original note would stop (only one note would play at a time). The dot on the BCN44 remained lit continuously, indicating constant MIDI input. The keyboard worked fine when used alone, and the BCN44 controls worked fine at all times. 

When I switched to our keyboard (Casio PX-330), none of these issues were there, and everything worked exactly as it should. Notes played properly, and BCN44 messages were sent properly. The dot on the BCN44 only came on when notes were pressed or released, or other functions on the keyboard were changed. 

This probably doesn't tell you anything you don't already know, but I find it was interesting that all 3 keyboards (including the one you linked) were Yamaha. Another thing I noticed is that the Casio is labeled as being "General MIDI" compliant. I don't really know a lot about MIDI messages, but from what I understand that means it complies to a standardized specification. So that could have something to do with why it interfaces properly with the BCN44.