Thanks, I am glad I could help. I know how aggrevating this could be.
I am using UBUNTU EEE, but I also got this to work on Puppy Linux, and DSL (damnsmalllinux)
I will try to refine my steps, and hopefully this will solve your problem.
1. in the linux terminal I sent sudo modprobe pl2303
2. I went to /etc/modules and added pl2303 to the bottom of the file
3. I plugged in the device and sent dmesg which should tell you where your PL2303 device is attached to. Mine was attached to /dev/ttyUSB0.
4. Iso then i sen cat /dev/ttyUSB0
5. I got no errors, but nothing was printing out at first, so I had to change the baud rate to 4800 by sending: stty 4800 < /dev/ttyUSB0
6. Then i sent cat /dev/ttyUSB0 again and started seeing NMEA sentences.
7. hit ctrl C to stop.