I am writing a very long document in word 2002 (say 300 pages) divided
into 7 chapters. All the chapters are based on one template (Thesis).
All the documents based on this style are set to update styles. The
template contains a style called Caption Body which applies the
following: Single line spacing, size: 10pt.

Everytime I open a document the style reverts to being the same as
Normal. If I manually change it back it stays for that session, but
once I save it and re-open it goes back to being the same formatting as
Normal, as does all text written in the style!

Anyone got any ideas about whats going and how I stop it?

Ian