Thanks all for the replies.
The book did eventually finish taking around 28 hours
It is also possible that I didnt supply enough info in my first post (learning curve) the book was a Dictionary and the completed/converted book had 19,996 pages. Each word/definition having its own page! This is obviously why it was taking so so so long. For those interested that works out at about 12 pages a minute.
As I have some more English to (other language) Dictionarys to convert it looks like I will have to get my hands 'dirty' and peer into the 'settings' to see if this behaviour can be restricted in some way and assuming I can understand the various variables.
Once again thanks to all and for the insight into the programme.
Alan