Sudden loss of serial port

OSX 10.6.3, MacBook Pro 2,1

I've used this Diecimila board successfully for quite a while now, and in the middle of a program today, using Firmata, I lost connectivity, and then could no longer find the tty/cu serial ports I've become so familiar with. This is the first time I've had this problem, but I have seen other people have it before.

I've spent a lot of time trying to find instructions on how to uninstall FTDI drivers, tried it several times, but never sure I'm actually fully getting rid of the driver entirely. I followed the instructions from FTDI, but I can only remove the kext, but never find the .pkg files it references in /Library/Receipts.

cd /System/Library/Extensions
rm -r FTDIUSBSerialDriver.kext
cd /Library/Receipts
rm -r ftdiusbserialdriver.pkg
rm -r ftdiusbserialdriverinstallerPostflight.pkg
rm -r ftdiusbserialdriverinstallerPreflight.pkg

So I repair permissions after deleting the kext and reboot. I reinstall FTDI driver, but during installation if I choose "Customize" I see that it is calling the installation an "upgrade." This makes me think I missed something on the uninstall. I reboot again, and still no ports when I plug in the Arduino. Blinking lights on the board and power indicator though when I plug in. What seems odd is that a couple of random times I've been able to get a port in Arduino, this 00000207D port (which is different from the one I'm used to.) When I list ports in Terminal I get something like:

tty.Bluetooth-Modem tty.Bluetooth-PDA-Sync tty.usbserial-0000207D

Then I start to think it's going to work. But when I try to upload the Firmata from Arduino, I see the serial lights blinking for a bit, but then they stall out too early, and shortly after I get:

avrdude: stk500_recv(): programmer is not responding

I've checked the board and tried both tty and cu ports. The last time this happened, I lost the port again and couldn't get it back by unplugging and replugging to the USB port, or anything.

Has anyone had any luck bringing their serial ports back on 10.6? Most of the examples I've found refer to older versions of OSX. Thanks in advance.

Have you tried on other computers? Maybe something happened to the board, not the software?