Hello,
thanks for your reply, my support level is "subscription only", so I can't open an SR.
I have checked the link, but as stated above we are using the latest driver and image for the card and since it worked properly until we did the upgrade to 5.5, I can't believe that the card or the SFP is faulty. I also checked if the card is supported in Esxi 5.5 - yes it is.
Regards
Peer