Fortigate 200A with no graphics

Hi, I have a Fortigate 200A with FortiOS 3.0 and FW Analyzer v5 (evaluation) on Centos 5.

My problem is that the fortigate appears in FW Analyzer, but only a few computers are displayed with very few information (after three days of reporting)
"Live Reports" graphics are empty, as well as many other reports which only show "No data available".

In "traffic reports", for example, a few hosts appear, but graphics show no traffic when there do is traffic passing through.

The Firewall has the syslog server configured with Minimum severity level=Information and Facility=local7. Also all firewall rules have "Log" option enabled.

I tried this very same instance of Analyzer with a Fortinet 100A and all graphics works correctly almost instantly.

Any idea about what's happening?

Thanks,

Omar