[otrs] customer (email-external) reply is not displayed in GUI

Hello, I have a strange problem with our OTRS installation. How we discovered it: 1. A user sends us an email requesting a new user account 2. Event is registered in OTRS, mail is sent back to user. 3. Agent resolves the ticket, closes and notify the user. The content of agent reply is "Requested user is created, have a nice day." 4. The user responds with an email. The content (as displayed in the web-gui) of the respond is "Requested user is created, have a nice day." The same as in #3. At this point we thought the user had just hit reply for some reason. But it turns out that the user actually wrote "The account isn't working". When we check the database for that matching article entry, we do see that is what the user wrote. We confirmed this by using /bin/otrs.getTicketThread <ticketID>. What we discovered is that the iframe (in index.pl?Action=AgentTicketZoom&TicketID=&ArticleID=) showing the content is using the wrong FileID. Iframe opens up this URL: otrs/index.pl?Action=AgentTicketAttachment&Subaction=HTMLView&ArticleID=&FileID=2 FileID=2 is the content of what the agent responded in #3. If we manually change the FileID to 1, the correct information is shown, which was "The account isn't working". Our DB is MSSQL2005. The article.id in question have this value for article.a_content_type: text/plain; charset="iso-8859-1" OTRS is set up to use charset iso-8859-1, defined in Framework -> Core -> DefaultCharset Does anyone what is wrong, and how we can fix this issue? Best regards, Tore