The Word-processor plug-in formats the citations and the paragraph they are inserted in using your “default” (Open Office) or “Normal”, “Standard” (Word) formatting. For many people this means that inserting a citation using Zotero will remove formatting such as indents, line-spacing, font size, etc. from an entire paragraph.

You can fix this by adjusting the standard/default format in your word processor.

If your styles and formatting toolbar is open (it is a pull-down menu with a list of labels such as “Normal”, “Body Text”, “Heading 1”) you can simply right-click on the “Normal” style and format it. Otherwise, select “Styles and Formatting” from the Formatting toolbar or the Format Menu. See here for the official Microsoft instructions, and here for a longer guide with screenshots.

In the “Home” Tab, first click on “Font” tab and choose the font and font-type you want to use and select “default” on the bottom of the window. You can change paragraph formatting (such as line spacing, indents, etc.) by doing the same on the “Paragraph” tab. There is also a “Styles” tab, where you can modify the “Normal” style. See here for a guide with screenshots.

In Open Office, open the styles manager in 'Format' > 'Styles and Formatting' or by hitting F12. Right click on “Default”, select 'Modify', and make the desired changes to this style.