I have a Macbook Pro (early 2011 model) using bootcamp to run both Windows 7 (64-bit) and Mac OSX 10.6.8. I can't get the FTDI drivers to work with either OS. I installed them from http://www.ftdichip.com/Drivers/VCP.htm. I'm using Arduino 022 and when I go to to Tools > Serial Port, there are no com ports listed. In my OSX it only lists 4 bluetooth ports. In Windows 7 the Serial Ports menu item is grayed out (I think, I'm not logged into Win 7 right now). I've had the Arduino running fine on my MacPro and a Win XP laptop, but I can't get FTDI drivers to work on my Macbook pro.
What Arduino board are you using?
Does it show up in (Windows) Hardware Manager or (OSX) System Profiler when attached?
What does dmesg (OSX) show when you attach the board.
I had this exact same problem the other night when I attached a FTDI Friend to my Diavolino (and MacBook Pro). After several reinstalls and reboots (just like the old windows days), I noticed that when I plugged the mini USB cable into the FTDI Friend, the little Rx/Tx LEDs would flash rapidly and dimly and there was NO reaction from the board when I plugged the Friend into the Diavolino.
I tried another mini USB cable out of my junk drawer and that did the trick.
Replace the USB cable.
There are a bunch of debugging aids out there but the first thing to do is to check the /dev directory to see whether the new USB device was created when you plugged the FTDI into the USB (http://forums.adafruit.com/viewtopic.php?f=22&t=18201). The other is to open the Console app and watch the log messages to see if there are any errors.
I did all that then replaced the cable and the world was good. Then I made the LED blink and went to bed. It was late and I am old. ;-)
I tried a new USB cable and it's working now!
Isn't that a cool feeling? I can't wait to add more parts and make it do useful stuff. Now I can get rid of all those 8051AH boards and UV-erasable EPROMs that I have been schlepping around since the 80's.