NO show graph of period last

[debora]

I have a problem now, when I want to see the period of days last not me show the graph, since I make to solve this?, instead of show the graph of the host, it does not show anything!!!, when clik in Period: [-2h+] no show , i'm runnig zabbix 1 month, zabbix1.1alpha7, mysql 4.1 y php 4,
look:

[Alexei]

Please do not make duplicate posts!