IIS 4.0, WebClasses and DCOM

I’m working on a highly transactional application, using IIS 4.0 as web server, VB 6 WebClasses, VB 6 DCOM components residing in a separate server and DB2/400 as RDBMS. Somehow IIS is unable to create DCOM objects afer a certain amount of transactions. And I have to restart the server in order to restore the service…. Any clue?