Trouble converting multiple JPGs/PNGs to PDF

Question

I'm using the education version of Adobe Acrobat Pro 9.3.3 on Windows Vista; when I try doing something very simple, namely selecting a group of image files (JPG and PNG, scanned pages from a book), right clicking to select "combine into PDF document," the result is one page which looks just fine, and the remaining pages look like grey, blown-up collages of the original images. When I try each page by itself (thinking I could later combine the resulting PDFs into a single PDF document), all image files except the first one come out looking the same--as if someone had blown up the image, overlayed numerous sections of the blown up image, and then grayed the whole thing out. The same problem happens when I try doing either from inside Adobe Acrobat instead of right-clicking on the image(s).
I have found a workaround, namely, to select all the images in the folder I wish to export, and right-click, select "print" and allow Acrobat to print from the resulting Windows Photo Gallery Viewer. But it's slow--and raises the question, why can't my Acrobat program just do this on its own? In addition, I presume that the workaround adds a step which means the resulting PDF is not as clean as the PDF would be if it had been created directly by Acrobat (e.g., there would be no additional margins etc.).
The reason that I'm using both JPGs and PNGs is that, when I tweak a JPG, I save it as a PNG in an attempt to keep the image somewhat "lossless."
Any suggestions or people familiar with this problem?
I tried having Acrobat clean up its installation, but all that did was eliminate the trash can from my desktop.
Thanks ahead of time to anyone who could help.

Answer 1

I have not tried BMP files, but do JPeg, GIF, TIFF, and PNG files regularly. I simply open Acrobat, then select the graphics files in explorer and drag & drop to Acrobat. I then organize the graphics if needed (using the pages tab) and save to a PDF.