Arduino Mega 2560 - Mac OS X 10.8 Serial Port

Hi everyone,

I just received my very first Arduino, it's an Arduino Mega 2560... First, here is my System profile: MacBook Pro (Early 2011) OS: Mac OS X 10.8.3 FDTI-Driver: Newest, just installed ;) USB 2.0 Ports... everything working... Newest Arduino IDE

Having looked into the Mac OS X Startup guide (http://arduino.cc/en/Guide/MacOSX), i knew there shouldn't be no drivers required with Arduino 2560... But the Arduino didn't show up... (Serial Port) I looked around in the Google search and found the FDTI Drivers - alright - installed! Starting the IDE.... Nothing. Reboot with connected Arduino -> IDE started -> Serial Port appeared (tty.serialmodemXXX). Wrote sketch, want to upload it: Port already in use :( Now: disconnected the Arduino, reconnected ... no serial port... Reboot, restart the IDE, reinstall the driver, deinstall the driver, use other USB Ports ... Nothing. When I connect the Arduino to my Mac, in the Console these notifications appear:

02.12.13 17:21:22,000 kernel[0]: USBF:  753.570 [0xffffff801b2fe800] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in.  It will keep retrying.  (Port 2 of Hub at 0xfd120000)
02.12.13 17:21:25,000 kernel[0]: USBF:  756.569 [0xffffff801b2fe800] The IOUSBFamily was not able to enumerate a device.
02.12.13 17:21:26,000 kernel[0]: USBF:  757.410 [0xffffff801b2fe800] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in.  It will keep retrying.  (Port 2 of Hub at 0xfd120000)
02.12.13 17:21:30,000 kernel[0]: USBF:  760.812 [0xffffff801b2fe800] The IOUSBFamily was not able to enumerate a device.
02.12.13 17:21:30,000 kernel[0]: USBF:  761.669 [0xffffff801b2fe800] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in.  It will keep retrying.  (Port 2 of Hub at 0xfd120000)
02.12.13 17:21:31,000 kernel[0]: USBF:  762.498 [0xffffff801b2fe800] The IOUSBFamily gave up enumerating a USB device after 10 retries.  (Port 2 of Hub at 0xfd120000)
02.12.13 17:21:31,000 kernel[0]: USBF:  762.498 [0xffffff801b2fe800] The IOUSBFamily was not able to enumerate a device.

I already looked around here in the forum, but nothing helped me... Not sure what to try next. It seems that the Mega is working just fine!