Problem with Open Office

[Roy Grainger]

Using Apple Mac - Open Office- I can produce and save a document, when I go 
back into it I only get a snapshot and am unable to access/enlarge and work on 
it. I can copy documents via a memory stick onto a Laptop (not an Apple) where 
I can then work on it.
Have tried deleting and reinstalling Open Office but get the same results. 
This has recently occurred and effects all of my documents.
Any help will be gratefully received.