Always double check every link in your documents to ensure that they are targeted correctly. Using the BASE TARGET tag will help with this.
With very narrow colums, or short rows turn the scrolling off by using the SCROLLING="no" attribute, otherwise a scroll bar may appear in your frame, hiding your contents from view.
Allow your readers to adjust the width of your frames as needed, make minimum use of the NORESIZE attribute.
To help make NOFRAMES compatible documents, use the server file include feature - <!--#include file="idx.html" -->. Ask your service provider if this feature is supported.