formula editor does not open

The formula editor does not open. It is not possible to edit any fields or selection criteria with the formula editor. When trying to open it the screen gets grey in grey and is blocked until the escape key is pressed. Then the screen is active again.

The formula assistant is working but does not give access to all fields.

I have a dual screen installation, but removed one screen without success.

Once the formulka editor opened when using the Micrsoft office communicator, but the effect was not reproducible on the next day.

There must be one internal parameter in the PC setup which has to be reset.

Who can help?