Early 2011UAS-2HnD not support SFP?

I have two Mikrotik 2011UAS-2HnD routers purchased in August 2013.

As far as I can tell these are the older 2011UAS devices with no power switch on the back of the box.

Software revision 6.33.1 firmware 3.24.

I purchased and installed SFP devices for the first time today.

Neither of them recognise the SFP device (an official Mikrotik S-85DLC05D) in each; I have tried swapping the devices round.

interfact ethernet monitor sfp gives this:

[admin@MikrotikLoft] /interface ethernet> monitor sfp1
name: sfp1
status: no-link
auto-negotiation: done
advertising:
link-partner-advertising:
sfp-rx-lose: no
sfp-type: (unknown)

The SFP devices both work as expected in a CRS-226 24G-2S+.

When either 2011UAS-2HnD is connected to the CRS-226 the CRS correctly reports that the module is present and the link is up.

At the other end, the 2011 never reports a module present or any link.

Any idea how to test, or does 2011UAS not actually support SFP?