In order for attachments to be indexed correctly for full-text search, the document in which the attachment is stored must have a field that contains text in the same language as the attachment. For example, if the contents of the attachment are in Chinese, a field in the document must contain Chinese text.
NOTE: This problem was corrected in R5.0.1, for customers using the UNICODE based indexing (which is the default method since 5.0.5, and available as an option since 5.0.2.)
If the attachment is stored in a document that does not have some text in one of the fields, Notes/Domino is not able to determine the language and character set of the attachment content. This may result in improper conversion of the attachment, resulting in the inability to retrieve the information during a search.
This applies to all languages that are represented by code-pages other than cp1252 (Latin1).