scanning to pdf

I kept getting an error when scanning a document and trying to save to pdf.

The error message was:

Error!
An internal error occurred while processing the document.
Click OK to close the program, and then try one of the following:

- restart the program
- restart the PC and then try again
- reinstall the Photo & Image Software and try again

[I have an HP OfficeJet 5710xi All-in-One running on Windows XP.]

I decided to try again, running HP Solution Center and scanning to searchable pdf instead. And it worked!

I noticed that the software sets the dpi to 300 and can't make it smaller. So the file is comparatively big. Then I tried pdf again at 300 and it worked!

Hmm. Try 75 dpi again. Error.
100 dpi. Error.
150 dpi. Error.

Shut down firefox (to increase available memory) and try 200 dpi. It worked!

OK, was it a memory problem? Try 150 dpi again. Error. 200 dpi worked again.

So it works 200 dpi and higher and errors on 150 dpi or lower.

The file size for 200 dpi was 155 KB. For 300 dpi was 332 KB. For searchable dpi was 345 KB (scanning an old Fairholme Fund statement). So might as well use searchable if going 300 dpi. Otherwise 200 dpi.

It seems the files could be smaller though. The newer Fairholme files are 144 K (and are searchable). Heck, the Schwab files are as small as 13K! (and are searchable too).

[4/20/10] I posted my solution somewhere on the internet. I'll find it again one day. [A few minutes later... OK, here it is.]

In the meantime, here's another guy that had the same solution. Plus some others with other solutions.

[4/20/10] here's one way to get the files smaller. scan in grey-scale or black and white instead of color. Black and white is substantially smaller than color.