PRS-500 and font scaling

[dorkydood]

I bought my wife a PRS-500 that has not been firmware upgraded by Sony. She has poor eyesight so I found calibre to adjust the font size in her books up to make it more comfortable for her use. I have worked out the necessary settings in calibre, however, now the reader will only display up to about page 8 before the screen shows no text at all. I have tried tweaking the settings, but am not getting anywhere with it. The converted .pdf file displays just fine on her PC in Acrobat and Nitro. The unconverted original file displays correctly and in full on the reader. Once I modify the font settings and convert the file, I lose most of the content on the reader.

Am I missing something simple, or is this just a limitation of the PRS-500 and calibre when you scale the font substantially?

Thank You in advance.

[dorkydood]

i hear crickets... ... ...