I use PDFcreator on my Win7 64bit system with office 2007, works fine.
Converting a 2 MB ".docx"-file with my preferences I get a 2.3MB PDF-file. Now I change nothing except installing office 2010. Afterwards I create a PDF from the same file using the same preferences and I get a PDF-file sized 32 (!!) MB.
I assume incompatibility with word 2010. Does anyone else encounter similar problems?
I also get this issue. I use pdf creator for batch printing word documents and since the introduction of word 2010 it has been producing much larger file sizes from the same docx word files. I suspect that Word 2010 renders the print job differently and it results in higher resolution images. I have found some guidelines relating to print file sizes on this forum and will try these and report back.