Performance problems during passive substitute approval

Hi,

I am having an issue during the passive substitute approval, most of the times when i use the passive substitute option the screen wth the SC is diaplayed but when i click on the magnifying glass or any other functions there would not be any response on the screen, the screen remains the same. Only some times it responds and displays the data and SC gets approved. When i approve directly as approver without using the passive substitute option it works fast and fine. I am not sure whether there is any performance issue in the server.

Please suggest how to fix this issue and make the passive subsitute screen also respond quickly.

Regards

GGL