PDF convert to PDF/A-1b problems

Question

I would like to convert my existing archive pdf files into PDF/A. I read on the forum that PDF/A-1b is less critical than 1a so I went with that. Using Acrobat Pro 9 and starting from "clean" (generated by Abbyy Finereader 8) pdfs, the conversion (using Preflight Conversion to PDF/A-1b) generally fails with the following errors:
Preflight profile 'Convert to PDF/A-lb (sRGB)" found the following errors:
xConvert to PDF/A-lb {1 object)
xFlatten transparency {high resolution) {1 object)
xRemove all alternate images {1 object)
       xDiscard hidden layer content and flatten visible layers (1 object)
       xDiscard hidden layer content and flatten visible layers (1 object)
       xRecompress LZW as ZIP (1 object)
       xPDF document is not compliant with PDF/A-1b (2005)
         xAnnotation has no Flag entry (42 matches on 33 pages)
         xAnnotation not set to print (42 matches on 33 pages)
I have no idea what this is all about. Besides, I thought I was running a conversion, so why doesn't it convert? Is there anything I can do?
PS. When I save a fresh scan using Finereader 9 set to generate a PDF/A file and I try to verify it with Acrobat Pro 9 (Verify Conformance..) I invariably am told the verification failed.
Luuk

Answer 1

I suppose it is more likely that Abbyy got it wrong than that Adobe did not implement the standard as they should have in Acrobat Pro 9? I did some further testing and put together a PDF file on the basis of tifs. I let Acrobat 9 OCR this file and subsequently converted it once to PDF/A-1a and once to PDF/A-1b. Only the last passed the verification by Acrobat; the former failed with a bunch of errors again (see enclosed screen shot). Am I expecting too much when I assume Acrobat can generate proper PDF/A-1a files on the basis of clean tiff files?
Luuk