Aspire R13 Outlook emails scrambling

Outlook emails, either received or while being written by me, will randomly scramble i.e. parts disapppear other blocks of text or image appear out of place, vertically and horizontally.  Close the email and re-open and it is fine.

It sometimes happens on opening an email, sometimes on scrolling down.

There is no discernible pattern to the type of emails affected or any other trigger.

There is no other problem with the computer which works fine.

Any ideas.

Thanks

Joe