Magento: Bundle items added but on reload they are empty

I go in and add items to a category for a bundled item. It seems it does it, and then opening again the category is empty.

How to trace this error?

Steps to reproduce:

1. Edit item - Bundle tab - Add Selected Product(s) to Option
   
2. Click on "Save and Continue Edit" button
   
3. I see a call to /index.php/admin/catalog_product/validate/id/481/back/edit/tab/product_info_tabs_bundle_items/key/8bee606f1ce09f1f0e2b4128v379e52e/?isAjax=true and am able to trace the Response (using Chrome's "Network" tab) with output {"error":false}
   
4. I see a call to /index.php/admin/catalog_product/save/back/edit/tab/product_info_tabs_bundle_items/id/481/key/371758eb16ca00ac50c8ca42e90d7559/ which has no response
   
5. Page redirects with "The product has been saved message.".
   
6. The edits are not there

I am using Magento 1.6.2.

Solved by editing the Suhosin variables suhosin.post.max_vars suhosin.request.max_vars file: /etc/php5/apache2/conf.d/suhosin.ini or you could add it to your site php.ini