Although PDF is an open standard it is also pretty vast resulting in some files that are at the edge of the standard. The PDF readers are only as good as the PDF data they can handle. The readers have to grow to handle the different kinds of data placed in the PDF file. If they don't they generally break on these edge cases. Generally the ones for Windows are the best because they have the largest user base and the developers of the readers are always keeping it up to date. The linux readers are probably slower in getting up to date to handle newer data and maintained by a smaller group that any updates take longer to address. Browser based viewers are also pretty well updated and maintained but again since the user base for Linux is not as mercial' as the Windows based group this might result in breaks. We use for GoldFynch and see this problem a lot. Sometimes the browser based viewer works fine for a PDF but our in app viewer (built on top of ) fails miserably. We try to stay active and update the munity as much as we can but it seems like PDF files can break it faster than we can fix it!