Domino Web Service, slow response first call

I have a Web Service that is to be consumed by .NET web applications. It take a XML string and parse it and then use info to create a document. Then return the link to the document in notes URL format.

The problem is that every time when this web service is called for the first time, it is very slow. Took up to 20 seconds for the URL to be returned. The WSDL profile says it took less than 1 sec to complete(total measured time). However, the elapsed time is over 25 seconds…

Subsequent calls to this web service complete very fast.

It feels like when the web service is called for the first time, it is doing some sort of caching?

Any of you have experienced this and can give me some hint as to how to solve this initial load/cache problem??

Really appreciate your time.

sze