ESXi 4.1 U1 shows also as Unknown in ITA 8.8.0

Hi all,

I was able to set up SNMP traps to point to my ITA server version 8.8.0. The problem is that after discovery and inventory the ESXi server are displayied in both groups VMware ESX Servers and Unknown. If I manually remove these servers from the Unknown group, they desappear also from the other group. Also please note that the status icon of these server is the grey question mark instead of the green one.

Thank you all for help.