Vista - MS Word 2003 on Vista. Delay when changing screens

I've been running MS Word 2003 (with Office 2003) on Vista for quite a while. I've had no problems other than a growing frustration at the delay that occurs everytime I change between word documents or back to a Word document from any other screen. As soon as I flick back to an MS 2003 word document there is a delay of between 2-10 seconds while my laptop stops and thinks. No such problem occurs when I flick between Excel docs or Powerpoint docs. I don't have any other problems with my laptop which is udner 6 months old.

The delay is driving me nuts as my work increasingly requires me to work on several documents at the same time. I've found some references to the problem being called DDD (Document Delay Doom) and instructions as to how to stop it for Word 2007 when running on Vista, but not for Word 2003.

Anybody any suggestions?