[Zope] Answer's Time

I'm having the following problem and wanna know whether it can be associated with Zope. I have a page in my system with various links, and when I click in a link, for instance link 1. The cursor starts being busy, the browser appear to send the request but there is no response. When it happens, if I open another window and click in the same link, I have the response immediately. It's tuly very weird... How can I debug it? I'm using Zope 2.74 with python 2.3.4. Suggestions will be welcome. Thanks and regards. Fernando Lujan