Resource hours difference in GME_RESOURCE_TXNS and in item cost calculation

Hi,

Resource hrs is mismatch in GME_RESOURCE_TXNS and Item cost view form hrs.In GME_RESOURCE_TXNS for eg total resource hr is 500 but in item cost form  actions->actual transactions it list Production batch,the sum of resource hr is 450.The difference is because in some Yield is given next month.But total resource hr in GME_RESOURCE_TXNS hits GL.But why those hrs not considered for item cost.

regards

arun