Hierarchy Node Selection Screen F4 Value delay in Display

Hello Guru's

We are now upgraded to BW 7 version with BEx 3.5.

I have two Hierarchy Nodes in variable selection screen in a query. When trying for F4 value display for Hierarchy node in the selection screen it is taking almost 8-10 Minutes time. But for the other Hierarchy Node of the same kind its not even taking 1 Minute. Can anybody help me in explaining what might be the problem here for delayed F4 value display of the Hierarchy Node ? Is there any solution to reduce this delay. Apprecitate if you can help me.

Thanks

Kishore K