Hi
If I understand you correctly whan you change your format from Landscape to Portrait it appears that "line breaks" are being inserted. If this is correct then the following solution will resolve your problem for the whole document:
1. Enter Ctrl+H (Search and Replace).
2. In the top box enter exactly ^l (for clarity this is a lower case l (el) not a figure 1).
3. Click in the second box below and entee one space using the spacebar.
4. Enter Alt+H.
This will replace every single line break in your document with a space and your document should display much better.
Let me know if you have further issues.
Good luck.
Tony(OTPM)