Hi,
I used a nice bluetooth framework called
"Marge".
There are many demo apps in the website. I used the blue chat demo as a sample to connect a nokia E61 to a ZEBRA bluetooth printer.
Remember to set the URL concatenating with the port (SERVICE_URL = "btspp://"+ remoteDevice.getBluetoothAddress()+":1"

in my case it was port 1.
Stefano.