ARD says my client version is too old, but it's not.

ARD 3.6.1

On the scanner windows, i see the computer I want to control.

The icon is pale blue, not blue like others.

When I double click on my client computer, under ADMIN panel,

arm says : Your client execute a too old software, it must have ARD 3.3.1 and up in order to...

The problem is ; this computer have ard client 3.6.2.

I installed it myself and double checked in system/library/coreservices/remotemanagement

I also double checked that the client have the right setting in Sharing preferences. (remote management...)

What should I check next?

I have 10 computers in my network, all under 10.7.5 or 10.8.2/10.8.3

I can control 3 of them, not more, all the same problem, and there is some with the black icon.

Thanks for the help.

Jean