Bad performance between Siebel and Word

Hi all,
we have a performance issue when create a COM object from a BS in Siebel:
var wordApp = TheApplication().COMCreateObject("Word.Application");
After clean all tmp word files the performance was good but when we restart the siebel services, once they are up performance become bad until one moment the performance come good again without we change anything.
We have reinstalled office but nothing, the problem persist.
We have checked the creation of com object outside Siebel and it's created quickly so we think the problem is between Siebel and Word but not always, something is damaged when you restart the machine or the siebel services and until it is fixed (we don't know how is it fixed) the performance is poor.