With some versions of Acrobat Reader and some other applications, some Lao characters in the files are incorrectly interpreted as punctuation characters and not displayed correctly. This is a problem with the original coding used for Lao, due to the absence of any accepted standard. A new coding convention (as used for the font Saysettha 2000) was introduced with Lao Script for Windows Version 5.30, and works correctly with Acrobat and most other applications.
However, the only generally accepted standard for Lao is Lao Unicode, so wherever possible Lao Unicode fonts should be used.
When creating PDF files containing Lao, it is generally advisable to embed the fonts in the documents, as those reading the documents may not always have suitable fonts installed.