It is important after you have collected for output your dat file that you rename the file using the same name as the pdf file. For example, if your pdf file is "product.pdf", then when you collect for output the dat file will be named "Assets.dat". You need to rename it "product.dat". This is important if you upload more than one product in a day. If you do and you don't change the name of the Assets.dat file you will have the second dat file overwrite the first one and then you might lose fonts. Font information is maintained in the dat file.