Each forum has a Sticky Topic, Before You Post. http://forums.adobe.com/thread/467760
Please start each thread with the edition and version of RoboHelp that you are using. I am assuming you are using RH HTML.
The code changed in RH7 and again in RH8 so I'm guessing the problem is related to the upgrade from 7 to 8, although that does really help us. It just maybe explains the difference.
The problem with lists is that many people have set up paragraph styles as list instead of using the LI tag. There are many posts on the forums about this. Also you might like to look at Willam van Weelden's pages at http://www.wvanweelden.eu/robohelp/lists/lists.php
Tags and spacing have not been an issue though. Try creating a new layout pointing to a new folder.
See www.grainge.org for RoboHelp and Authoring tips
Thanks for your reply. Most of the formatting and spacing issues were resolved when the trouble was traced to Internet Explorer 8. Setting IE 8 to Display all webites in Compatibility View resolved most of the issues. The other issue was a complex topic with numerous conditional tags that could not be resolved except by starting all over again and redesigning the topic. I essentially created two topics and applied conditions at the topic level to solve the problem.