In the past few versions of PDN, all files open as 96dpi on my Vista 64 machine (and then save as 96dpi after any changes have been made!), regardless of the file-type or original resolution. On my Win XP 32-bit machine, the same files open at their correct resolutions. This is a serious problem and for the time being I have had to abandon PDN on my vista machine altogether.
Unfortunately it took a while for me to notice this bug, and a number of important illustrations that my wife was working on for a publication ended up being silently converted to 96dpi, all of which now have to be re-scanned and started from scratch on our XP machine.
I can verify the bug by doing the following:
1) Make new file @ 600dpi, save as any file type (I've tested jpg, tif, and png)
2) Close PDN
3) Verify with Windows that the file did save as 600dpi
4) Reopen the file in PDN
5) It opens at 96dpi, and any changes made force the file to be saved at 96dpi, losing their original resolution.
The same thing happenes if I open a 480dpi photo, edit, and save. It saves as 96dpi.
I'm running stock PDN installs with no modifications, plugins, etc.