Multiple KPI Web Parts in one page = Endless loading time

As I've surfed and googled for two days now, and could not find any answer to this question, I thought it was enough time to ask this.

Ok, first of all, data structure:

In a SharePoint Site Collection, a user has created four subsites. In each of these subsites, he has approximately 8 lists that contains data.

From this data, for each SubSite, he has created an Status Indicator List. With the data from these lists, for each subsite, he has also created in the Home Page for each of them an WebPart. They display the Indicators from these lists mentioned before.

And now the issue:

In the main Site Collection Home Page, the guy wanted to display the same webparts he had in his subsites, as an "Resume".

Thing is: When he inserted the first WebPart, everything worked fine. Data loaded, Indicators were correct.

When he inserted the second WP, the second one started to load, but never finished. That happened when he inserted the 3rd and 4th KPI WP.

Then, he contacted me. Important to consider that...

It's not a data connection issue, since I've tried to load the same lists the SubSites WebParts load and all of them are correct. Also,

It's not a browser issue, already tried with many other browsers (Firefox (3.6, 7, 8) Chrome (10, 11), IE (8, 9))

And what made me come here, because I could just conclude that there's no way to display more than one KPI WebPart per page:

When you're in Page Edit mode... All KPI WebParts load correctly!

What I've tried so far:

- Change WebParts zone, zone index, position: No effect.

- Create them in another page, inside Doc. Library: No effect.

- Export the webparts in the SubSite pages, re-import and Add to the Site Collection Home Page: No effect.

Could you please help me with this? Thanks in advance,

Erich.