I've done a lot of work with Device::SerialPort, which is the unix implementation of Win32::SerialPort. I get just a single "0" value when I have something in my settings wrong. Usually it's a baud rate. (My hardware at the other end doesn't always honour it's DIP settings for the baud rate) The other condition that I've had generate that was an error in flow control settings.

Maybe try a test at 2400 or something.

In any case, do please x 1000 use Win32::SerialPort, because it is what is normally used, it works _very_ well, and people expect to see it. Also, it's interface is portable to other platforms. (for example, the native platform of Perl...)
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