The way to test this is to get two BlackBerry handhelds - one that is displaying attachments correctly and one that isn't. Forward the E-mail message with the attachment that the BlackBerry handheld will not display to the BlackBerry that is displaying attachments and forward the E-mail message with the attachment that the BlackBerry handheld will display to the BlackBerry handheld that is not displaying attachments. I believe you will find that the fault follows the attachment rather than the BlackBerry handheld.

A common issue with attachments occurs with PDF attachments - if the PDF is created by an Adobe product it works OK but PDFs created by third party products commonly fail. The Attachment service converts the attachment to a proprietary BB format and if it can't convert the attachment correctly then you will not be able to display that part of the attachment.

If this is a major issue to you then you may have to upgrade to the BES 4.0 solution as it has a more advanced Attachment service engine than BES 3.6.