The tab settings are in the TOC styles. Set them so that the dot leader appears in all versions. To do that, adjust them in the setup that causes problems and they should be fine in the others.
- The different setups you describe may have different printer drivers, even if the same printer. Word uses these settings to setup its pages.
- The loss of the dot leader is caused by an intervening tab setting that is intercepting the tab to the edge with the page number. Chances are good that you do not need that tab setting.
Resource:
TOC Tips and Tricks by Suzanne Barnhill, MVP