Please refer to the following steps to remove JPEG2000 image compression from your PDFs. This format is not supported by Yudu and can lead to discrepancies between versions.
1. Please check the PDF is using JPEG2000 by opening the file in Adobe Acrobat Professional. Open up the ‘Preflights’ menu - In Acrobat 9 this can be found under the Advanced > Print Production > Preflight tab. 
2. Here you will need to expand ‘Acrobat/PDF version compatibility’ at the top of the menu and double click ‘Compatible with Acrobat 3’.
3. After the process has run you will see a list of incompatibilities. If you see ‘JPEG2000 compression used’ then you will need to run the PDF Optimiser in order to convert these to a suitable format.
4. Run the ‘PDF Optimiser’.
(In Acrobat 9 this can be found under Advanced > Print Production > PDF Optimiser. In other versions it will be located under File > Save As > Optimise PDF.)
5. Check the ‘Images’ checkbox is ticked on the PDF Optimiser and make sure the following 2 options are set:
a) ‘Make compatible with’ is set to ‘Acrobat 4.0 and later’
b) Tick ‘Optimise images only if there is a reduction in size.’
6. Press OK and save the file - This PDF is now ready to upload to YUDU Publisher.