I am using apache fop 2.0 for document generation. I was using auto-detect feature to detect fonts from the specified directory. This directory contained two font files (.ttf, .pfb) for a same font; earlier this setting used to work for me. Until I upgraded my linux kernel version and It started picking wrong font file, so while generating PNG document I am getting error "Glyph not found" for some characters and document generated is garbled. To fix this error, I added the manual font mapping to .ttf file along with auto-detect. This fix worked but it caused latency to increase. Any clue on this behaviour?