Untangle Session count Drops after 25000

I have an untangle box with specs Xeon E5-2407 Quad Core 2.20Ghz, 16Gig RAM, 1TB HDD. im passing about 60Mb/s through the box. i have about 3000 Devices passing through the box. my problem is that when my session count on the box reaches just above 25000 it drops and restarts all connections again.

i have attached am image of the session viewer on my reports.

Please assist.

Attached Images

• DPI2.png (69.5 KB)