caching Problem

HI all,
In my project I have common classes called order.java and orderline.java(in a cached folder) that fetch results for 3 reports, there is a particular method in order.java that evaluates linefill.

say Order has 3 order lines
order line is line-filled 100% if requested quantity has allocated quantity
else linefill = alloc quan/req quan

Now line fill for an order wouldbe
no of line having linefill 100%/total no of lines

I am getting linefill as 100% for certain orders which still have certain order lines with less than 100% which is not according to our expectation

When I restart the server this intermittent issue is solved
I call this an intermittent issue bcause it is after a while that such discrepencies occur.
Please suggest as soon as possible

lalithaputra2005@yahoo.co.in