Since I'm new to using Arduino devices
may I ask if you are talking about a driver on the Mac or a driver on the Arduino chips?
In my mind that points towards an error in the Arduino 1.0.1 software.
No modifications of the Arduino environment are needed, simply install the SiLabs USB drivers ...
Version 2.6 Corrected all known Kernel Panics for 10.4/5/6 for surprise removal and data transmission Corrected an issue with data drop while using XON/XOFF flow control Corrected RTS/DTR toggling sync issue Version 2.2 Corrected Kernel Panic in Snow Leopard which would randomly occur after transmission