Do you mean 905 or 905i?

There are two cables that come with the 905i.. one works with the N900 the other works with the iphone.. Try the other cable..

The cable has three rings on the n900 end plug.. You can use the adapter that comes with the bh-905 to change it into a 2 ring plug.. That will also work..

In the headphone case, is there a D shaped pouch that comes out? This is a 905i case

How can you tell if you have 905 or 905i headphones?

Are there elastic loops on inside the case that the adapters and plugs fit into? This is a 905 case

In the headphone case, is there a D shaped pouch, a bit larger than the N900 that comes out? This is a 905i case..