Cannot upload Blink Sketch to new Esplora (Mac)

I have a new Esplora board and IDE v1.0.5
I have selected the Blink Sketch and tried to upload it. But I get a message about being unable to upload to a Leonardo on the selected port. I understand the Esplora is based on the Leonardo so I followed the instructions about pressing the reset button first. The "On" and "L" LEDs light up, but no Tx/Rx

I checked the port is active by switching to the Uno (rev2) and using the blink sketch on that. No problems.

Please can anyone give me some advice?

Thanks in advance

I feel so stupid. After hours of research and faffing about I went to play with the RaspPi, trying to use SSH or VNC. This tied up the USB lead I was using.

"I'll have one last try", I thought, and grabbed the cable for my Kindle. Up popped the message about an unrecognised keyboard being connected. Off to load Arduino IDE (1.0.5) and everything is working.

Moral of the story - check the cable!