I am having the same problem as well. I have reinstall NETpbm and verified the libraries. I get the same error (Error: Unable to make thumbnail (0)!) whether I choose Upload a Picture from Gallery or if I use Remote Gallery.
Adding Sample.jpg
Warning: exec(): Unable to fork [cmd.exe /c c:\netpbm\bin\jpegtopnm --quiet \albums\PoolParty\Sample.jpg | c:\netpbm\bin\pnmscale --quiet -xysize 150 150 | c:\netpbm\bin\ppmtojpeg --quiet --quality=95 > \albums\PoolParty\Sample.thumb.jpg] in C:\Inetpub\wwwroot\Gallery\platform\fs_win32.php on line 161
Error: Unable to make thumbnail (0)!
Posts: 8194
This is *not* the same error. Split. Please tell us what server you're using...