There was an update to the Intel Ethernet drivers to fix an incompatibility with the J9285B and similar cables. I suspect that you are encountering that issue. Updating the drivers will be a good next step.
The latest Linux driver is at http://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=14687.
Directions for getting the latest driver for ESX can be found at http://www.intel.com/support/network/adapter/pro100/sb/CS-029808.htm.
Let me know if this solves your issue or not.
I downloaded the latest driver for ESXi 5.0 (ixgbe version 3.9.13) and I still have the problem there.
On the Linux front I am using SLES 10 sp4. I downloaded the 3.9.17 driver and compiled and loaded it. I checked and it says I am using ixgbe version 3.9.17-NAPI (firmware version 0x546c0001).
I am not able to get traffic to go out through the cable. There are solid green lights at both ends with another green light flashing.
I really frustrated here. HP tech support tells me that I can only reliably connect HP cables to the HP switch, Intel says I should use Intel cables. So I'm getting nowhere fast.