Nexus5548UP and Catalyst2960X

Hi guys,

Wierd problem....

I am uplinking Nexus5548UP with catalyst2960X using GLC-LH-SMD= SPF. The port on Nexus end does not come up(is down/down), but on 2960 it show up/up (line protocol up). 

when you shutdown Nexus port, 2960 interface goes down proofing that there is some sort of active connection.

when using the same SFP, same cable  between 2 Nexuses the ports come up/up (line protocol up), working 100%

Anyone experience same issue before? What is stopping the link to come up between nexus and cat2960?

Any suggestion would be welcome.

Regards

Modifa