I’m experiencing two problems right now and would appreciate any help to get around them.
1st: While writing, I use Courier with line spacing set at two. Before compiling to Mobi, I change my font to New Times Roman (which works fine) and then I set the line spacing to 1.5.
Problem: When I try to set the line spacing, only the first paragraph will change to 1.5. The rest of the document remains at 2.
2nd: After compiling to a Mobi file, I view the output with the Kindle Viewer.
Problem: The Kindle Viewer shows that the chapter and sections titles are not centered properly. Yet they were correctly centered in Scrivener.
I’m not sure exactly what you are doing, so it’s hard to say. Are these changes being made at a global level with the compiler, so that your text is automatically cleaned up to a certain style? Are you going through one document at a time and using the Format Bar and other tools to change the text? If so, which buttons and menu commands are you using? Or are selecting many documents at once and using Documents/Convert/Formatting to Default Text Style? Etc.
Something worth mentioning here is that none of this really matters if you’re making a Mobi file. Line-height isn’t something you control, that is set up by the end-user reader device or software preferences. So just not worrying about it is one option. Line-height is actually stripped out by Scrivener when you compile, in accordance with Amazon’s publishing guidelines. Likewise you have no control over fonts, but in this case you may want to switch out of Courier for compiling as that is the one exception to fonts otherwise not being something you’re in control of.
Again it would help to know what your setup is and what actions are you are taking. One thing to consider though, if you’re using the compiler to clean up the text formatting, and the text in part includes hand-typed titles, then you probably have a good chunk of your answer right there. If the compiler converts everything to left-aligned that includes any text you may have set up to look like a title. Make sure to use the Format/Formatting/Preserve Formatting command on any text that should not be altered by the compiler.