USB modem problem on mac osX10.6.4

dear all,
I have a arduinouno board aim traying to connect to a MacBook with mac osX10.6.4...
I followed the instruction, but...as soon as I connect the usb cable I get a message like...

usb devices using too much power disconnected...
and I do not see any usbmodem in my list of serial ports...

what can I do?

thanks a lot, and regards

usb devices using too much power disconnected..

Is there anything connected to your Uno?

I tried it with som wiring ... and totally empty...

looks like is a mac broblem tough...

what can I do?

Assuming there is nothing wrong with the arduino and you don't have a short circuit connecting things up then you are taking too much power from the USB port. On my Mac min the keyboard USB connections are limited to 100mA, check what current yours can supply. You could try a powered hub.