CentOS 6.3 + EPEL, all updates applied
$ rpm -qa |grep zabbix
zabbix20-2.0.4-1.el6.x86_64
zabbix20-server-2.0.4-1.el6.x86_64
zabbix20-server-mysql-2.0.4-1.el6.x86_64
zabbix20-web-mysql-2.0.4-1.el6.noarch
zabbix20-agent-2.0.4-1.el6.x86_64
zabbix20-web-2.0.4-1.el6.noarch

Attached screenshot of import screen.

have you been doing any direct database modifications now or at any point in the past ?
it does sound like ids getting out of sync.

if you do :

delete from ids where table_name='hosts_groups' and field_name='hostgroupid';

does it start working ?

I have not. As a matter of fact, when I went from 1.8 to 2.0 I was so paranoid about messing up the DB that I did a fresh install.

I realized that you wanted me to run that SQL statement either way so I did. When I did it as a select statement instead I got this:
mysql> select * from ids where table_name='hosts_groups' and field_name='hostgroupid';
-------------------------------------+

-------------------------------------+

-------------------------------------+
1 row in set (0.00 sec)

When I ran it as a delete statement I got this:
mysql> delete from ids where table_name='hosts_groups' and field_name='hostgroupid';
Query OK, 1 row affected (0.01 sec)

After that, I tried importing again and got this error

Error in query [INSERT INTO hosts_groups (hostgroupid, hostid, groupid) VALUES (268, 10167, 1)] [Duplicate entry '10167-1' for key 'hosts_groups_1']
DBerror

Did you edit the XML file by hand? It's structure is incorrect. It has multiple groups and items tags.

It's a common problem with the API. When we call, for instance, host.create and pass duplicate host groups to a host, it will cause an SQL error. Same for other methods. It will be fixed in the trunk, not in 2.0.

CLOSED.