I believe that some CorasWorks sites used unghosted (customized) pages.
You can reset pages on a page by page basis using either the browser or
SPD. Ask if you need detailed instructions on how to accomplish this.

I will run the reghost utility and see what could have cause the issue, I
inherited this environment...my tasks are to make it work finally so I am
trying to find the solutions for many problems that I have encountered so
far.

orasWorks have a tool for updating the page layout and chrome of
their unghosted sites, called the Design Migrator, it can be used
against 03 upgraded sites or 07 to 07 (to change chrome & page
layouts).
Basically, what you do is:
Create a site in 07, using CW 07 templates or from a basic team site.
Customise the page layout with SharePoint Designer, adding your web
part zones (taking care to have the correct IDs to match 03 ones)
Run the tool against your old sites, pointing to the page you did in
the new 07 site as a 'template'.
Click go and it incorporates all the nice new 07 look and feel to old
sites.

I had excatly the same issue  and found it works a treat. You can even
get clever and remove/relocate original web parts and zones to your
taste. It also fixes list views which are sometime broken during
upgrade.

we will not use coras works in this version of the
company's portal I have the upgrade for coras works and will give it a try
and will let you know how it works for me.