Thanks for your help.
With a bit more research it turns out Intel card requires Intel SFP+ modules ( Not mentioned on the Dell web site) and will not work with the dell ones I have.

http://www.intel.com/support/network.../CS-030612.htm


So I now have one on order that should sort it out but will keep you posted.

Good point about the uplink port but I have not found anything that would suggest a proprietary protocol. The module in the switch is a U691D SFP+ one.

Many thanks again.