Hi Raoul,
first of all you can switch to the "old" editor easily by navigating in your form. Tried this?
Do you develop a smartforms here? Then you have to swithc to the full screen editor and afterwards change editor.
Next step would be to switch the whole system to the "before" word editor.
You can do that via the report RSCPSETEDITOR.
See this SAP OSS for more information, I think this is your issue:
791199 - Default editor changed to MSWord in SAPscript and SmartForms
~Florian