Unknown health status - OME 1.2 - ESXi 5.1

Hi guys, OME is not recognizing traps from ESXi 5.1, this is an example:

Enterprise: .1.3.6.1.4.1.6876.4.90 Trap Ids:Generic:6 Specific:401; (;0= 07 dd 07 20 0e 39 19;1=135.100.0.237;2=1.3.6.1.4.1.6876.4.90)	Unknown	Unknown

OME shows health status as unknown.

Any idea?

FM