I would suggest that you download and install Kindle Previewer (
http://www.amazon.com/gp/feature.htm...cId=1000234621 ) and use it to preview your MOBI conversions. Kindle Previewer is designed to emulate the Kindle devices and the Kindle for iOS apps (iPhone & iPad).
If you are using Windows, do the following after installing Kindle Previewer:
- Open any folder window and use the Folder Options applet found on the Tools menu. On the File Types tab scroll down to find MOBI and use the Change button to set Kindle Previewer as the app associated with the Open function. This makes Kindle Previewer the defaut app for viewing MOBI files. I would suggest repeating this for AZW and PRC as well.
- In calibre's Preferences go to the Behavior sections and uncheck MOBI (and AZW & PRC) in the right column labled "Use internal viewer for:".
Now when you try to view a MOBI file in calibre the Kindle Previewer will be used instead of calibre's internal viewer. The calibre viewer is good, but Kindle Previewer is a much better tool for the purpose of previewing the books behavior on a Kindle device.