Issue using SCO java SerialDemo

I recently installed the Java Communications API (v2.0Aa) on SCO and I'm having some issues running the SerialDemo application that comes with it.

I can open a connection and send text from SCO to a toy windows app I wrote - that works fine. However, when I try and close the connection, I get the following error:

libthread error: _thr_sigacthandler: fault 1 inside a critical section

What follows after that is a mass of debug text with various values (I don't know what any of it means). Can anyone suggest anything I could read up on to try and figure out what the error actually is? Is more information stored in log files anywhere?

If it helps at all, the offending line in the java program is when the SerialPort object is being closed.

Any suggestions are welcome. I didn't want to immediately just dump the whole thing here and hope someone else can glean something useful from it.

Are you running the java application as root?
Does the serial port have getty or uucp enabled?
Is it COM1 or a port on a multiport serial card?
Do you have MP5 installed?

Yes to root.
Not sure as to the getty/uucp question.
Yes to COM1.
Yes to MP5 being installed.

This actually ended up being something of a non-issue. When I actually went to develop the java app I needed, I didn't ever encounter problems closing serial ports. Still not sure why the demo explodes, but at this point I don't really care.