Widgets disappear by clicking on widget area

Hi,

We use Attitude for a small business and have a problem with the widgets.

We had two text widgets and two of the costum widgets.

Today I clicked on widgets in the dashboard area and all exisiting widgets were gone.

Always when you add a new widget and go back to the widget overview site wp-admin/widgets.php the former created widget is gone and not displayed anymore (website and admin area).

I tried to delete all 5 plugins – the same error.

I called our hoster – we have a php memory limit of 128 mb.

What can we do? Thanks for help…