Tested only with java Web Start. Command line for launcher:
/usr/lib/jvm/java-6-sun-1.6.0.26/bin/javaws "http://soft.bt747.org/BT747_J2SE_Latest_rxtx2_2p2.jnlp"
In menus select:
Settings - Device Protocol - "Holux M-1000C / GPSport 245"
To connect to device via USB data cable (not USB power cable from HOLUX package):
"USB" "115200"
"/dev/ttyACM0" "115200"
or via blueman (pincode for pairing 0000):
"/dev/rfcomm0" "115200" (port must be not used by gpsd)