I am using:
Windows XP SP 2
Acrobat Professional 8.1.2
Microsoft Office Professional 2003
I have had this problem for several years through different versions of both Excel and Acrobat.
When converting an Excel Worksheet in which I have copied and pasted a 'Word Drawing' (in my cases, it is a graph) to PDF, there appears to be graphical noise that appears in the resulting PDF around the graph. When zoomed in, you can see that these pixelations are actually parantheses characters rather than just random visual noise. This happens no matter which way I choose to convert to PDF, both using File->Print->Adobe PDF or by just hitting the Adobe PDF button at the top of Excel.
Here are some screen captures to illustrate what I am talking about:
Graph noise - Zoomed out
[img]http://i42.tinypic.com/2mctu84.jpg[/img]
Graph noise - Zoomed in
[img]http://i41.tinypic.com/whjm0z.jpg[/img]
I would be glad to email you the WORD/EXCEL/PDF if that would help resolve this issue. It would be much appreciated. Thank you.
Now, if you have a PostScript printer, the other thing to check is if the same artifacts are seen when printing to a PostScript printer. In that case, this would be a problem with Microsoft Office.