Why are you telling me that my document is "upside down"? In a routine fax transmission, page orientation (top of the page first into the machine or bottom of the page first) is not critical because the reader can easily flip and arrange the pages to read them top to bottom. However, it is critical to our process that each page is faxed top to bottom with the top margin being fed first into the machine. Once they have been received in PTAS, fax transmitted assignments are processed strictly by electronic means. Although the PTAS software can rotate a document 180 degrees for viewing purposes, when the electronic document is extracted to generate the archival microfilm record, each page is extracted exactly as it was first received. Accordingly, a document sent "upside down" would be microfilmed upside down. To further complicate matters, because the system generated recordation and reel and frame markings on the pages would be in the opposite orientation, the resulting document would be difficult to read.
Numeric stability is probably not all that important when you're guessing.