condition record not shown in billing

Hi,

i created a sales order which has a discount for example xd10 and the condition record is picked correctly in the invoice. pricing analysis also shows the condition record..

However when i do the billing, this condition type is not picked in item conditions in pricing at billing, in the analysis no condition record is shown even though a condition record has been maintained.

could any one let me know any reasons for this?

Thanks

Keshini