Arduino software doesn't locate connected nano

I have a Nano controlled lighting project that I'd built at home to be installed in my workplace, which I recently brought in. While working on it at home connecting its USB cable would cause it to be quickly detected by the Arduino software on my MacBook Pro running OSX10.6 (Snow Leopard). I'd planned to update its software from my work laptop (a MacBook Air running OSX10.7 (Lion)) but for some reason the Arduino software never recognizes the USB connection. I've brought my personal laptop in and that still works with no issues.

Other USB devices seem to work fine (ie keyboard, mouse, ethernet adapter), so its not the USB interface itself. Anyone have any ideas on this, or pointers to q troubleshooting guide for this sort of thing?

Did you install the FTDI drivers?

I hadn't explicitly installed the drivers (I don't think I had on my personal MacBook Pro either) and didn't think they were needed for the Nano v3 (as implied by http://arduino.cc/en/Guide/MacOSX). However I now have installed version 2.2.18 of the drivers and the board still does not appear when connected to my MBA. Any other ideas?

From that page:

If you're using an older board (Duemilanove, Diecimila, or any board with an FTDI driver chip that looks like this:

The Nano uses a FTDI chip.

If serial port isn't showing up, perhaps the FTDI is dead.

The problem here is that the same board shows up fine on my person MacBook Pro, but I can't get it to show up from my MacBook Air that I have at work. So the Nano itself seems to be fine. I'll try reinstalling everything again and see if that clears anything.

Does it show up in "System Information"?

Use spotlight or: Apple -> About this Mac -> More Info -> System Report

It didn't at the time. I uninstalled the Arduino software, then reinstalled it and the FTDI drivers and it appears to work now. Thanks for the help!

Again, the Arduino software has nothing to do with it. It was the FTDI drivers.