Check your scanning compression, uncheck all and work your way backwards...
We did this with a helpdesk tech from Xerox and eliminated our issues.
This was done from the Admin Webpage though not the front Panel.
All things are difficult before they are easy.
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I turned that on and off but it didn't seem to resolve the mix problem. To get it into the document I open it (the pdf) in Acrobat, crop to the frame of the map, copy and then paste into ppt. What's bugging me is that it worked with one of the maps and not the other two. I don't remember how I did it differently. I find that under image only settings, the graphic becomes very light and grainy and the letters appear with the same graininess. I tried the tiff format output from the 5655 and it made the text grainy as well.
Are you using text searchable option? How are you bringing the document into word/pp?
If you use a pdf converter program such as PDF Converter 7.0 it should work fine.
I'm using a Workcentre 5655 for scanning to generate a PDF of a map which I can then extrac a part of the paget and copy to a Powerpoint page. The PDF arrives via email okay and looks okay. However, when I block, copy and paste it into Powerpoint most of the text (that isn't within the land drawings of the map) disappear. Things like legend or title. Looking carefully at the PDF, it appears that the land drawings are grayscale while the text is bitmap. Anything bitmap doesn't seem to copy successfully to any office app (i.e power point or word). I've tried numerous options available on the 5655 keypad. Somehow during this, I was able to create one that didn't have any bitmap but I don't know how I did it.