'Inventory Scan' on Console is disabled

Hello,

we are installing some Agent on customer machine but for some installation we see disabled the 'Inventory Scan' option on server Console (All devices --> rigth click on device --> Inventory Scan).

We have installed these Agents

HP-UX 11.11   ----->  line disabled

SOLARIS 9     ----->  line disabled

WIN2003 ser   ----->  line enabled

WIN2000 ser   ----->  line disabled

Sometimes if we do a refresh we see the line enabled but just after we see the line disabled.

When, with refresh and 'inventory scan' enabled, we do an inventory scan we have these error:

HP-UX 11.11   -----> the remote system refused the network connection

SOLARIS 9     -----> CBA 8, unable to contact the remote Agent

WIN2000 ser   -----> Not specified - but if we see the inventory, we see the 'Last Updated by inventory server'  date that is not changed

For all these 3 machines, if we do rigth click on device --> properties --> Agents tab

we see that the 'Common Base Agent status' is 'Not loaded'.

Could you be so kind to help us to resolve these problems ?

Thanks for your support.

Andrea.