[Newbies] Sending messages over Bluethooth "serial port"

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Hi guys,

I am trying to write some code (in squeak) to talk to the Lego
Mindstorms NXT. Therefore I need to communicate with a Bluetooth
"serial port".

I can connect to the port using the SerialPort class (at least I don't
get any message that tell otherwise), but when I try to send any
message to the serial port Squeak doesn't response anymore. When I
turn off Bluetooth I get an message like: "Error: a primitive has
failed."

I am working on Windows XP (in case you want / need to know)

Are there people who have succesfully "talked" over the Bluetooth "serial port"?

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