Uploading Error - Leonardo, OSX - Yosemite

Hi,

I am using the latest Arduino Interface on a Max running Yosemite. When I try to upload anything (including Blink) to the board (Leonardo) I get the message:

Binary sketch size: 9,368 bytes (of a 28,672 byte maximum)
Found programmer: Id = "Humidit"; type = d
    Software Version = H.u; Hardware Version = m.i
avrdude: error: buffered memory access not supported. Maybe it isn't
a butterfly/AVR109 but a AVR910 device?

This does not always occur but when it does the only way I can resume communication is by restarting the computer.

Any help appreciated,

Alex