Availability Statistics problem

Hi guy,

We are using OpManager 7 and its working fine. Only problem is since last month 19, availability data is not being saved to OpManager. When i click on a device (any device router, switch, servers etc... all are same) and show availability for last 30 days it shows the following:

Availability Statistics
Options Uptime(%)
Today 100.0
Yesterday 99.639
Last 7 days 0.0
Last 30 days 100.0
This week 0.0
Last week 0.0
This month 0.0
Last month 99.919

As you can see we don't have any data for last 7 days, 30 days, this week, last week and this month.

Any idea what's causing this?

Any reply is appreciated a lot.

Thanks

Delgee