Problem on pages with modules

[EsquireX]

Hello,

I would like to know why, for example, after logging in my forum, it opens from a different place than where I placed the "{cms_module module='PunBB'}" tag?

This also happens with my Singapore Gallery page (after clicking a picture the result is in different place).

Any ideas?

[katon]

Same thing.  In the login page source, the login form shows:

How do I change the action value?
Does anybody have an answer or a suggestion where to look?