Really struggling with quantize on DJM900

My Nexus has just arrived - and lovely it is looking too - but I ma having real trouble getting the quantize function to work. I think I have got it all set up right, LAN hub, tracks analysed in rekordbox, quantise function turned on on the cdj2000s (also set their numbers to match the audio channels they are conencted to) but still I only get the flashing beat sign when I press the quantize button on the mixer. I am using the Netgear 10/100 Mbps fast Ethernet switch to connect all the cables.

Any help out there?

Thanks in advance

Bill