I found a good bit of advice on one of the Amazon Kindle threads. (This is my interpretation).
Before you upload to Kindle it would be best to check your formatting as Amazon converts it using HTML. If you are using Word go to Tools > Word options > Display > tick all the formatting tabs > advanced > tick the 'mark formatting inconsistencies'. Have a look at your manuscript. You might be surprised at what you find!
I had written my book many years ago and used tabs, so had to remove all the tabs and use the set paragraphs instead.
