Service Studio blocks in debugging mode and my pc is configured as server

Whenever I try to debug a web application in my machine acting as Server and using Service Studio, it blocks and the web page does not open.
If I do the same using Publish, the web page opens and it is ok. There is no blocking web page.

May the ports on the firewall be blocking that? What can I have to do?

Is there any special configuration in Service Studio?

I have AVG and Service Studio free version installed on my pc and the operating system is Windows Vista.

How can I solve this problem?

What do you mean by "it blocks"? What is the precise behavior you are seeing? Without more details, it sounds like you have a breakpoint somewhere that you are hitting and do not realize it. You will know that this is the case if the Taskbar item for Service Studio is orange or flashing indicating that it needs attention.