Version: 0.8 Portable Revision 2
The release of SumatraPDF Portable 0.8 (Rev 2) seems to have a bug since there was an extension change on the settings file.
The old launcher for SumatraPDF 7.0 and below was handling a sumatrapdfprefs.txt file, but in the new release [0.8] SumatraPDF stores its settings in sumatrapdfprefs.dat. The new launcher isn't accomodating for the new file type, and therefore sumatrapdfprefs.dat is not being copied to the data directory on close.
It looks like if an old sumatrapdfprefs.txt is in the program directory, SumatraPDF will read and use these settings, however I'm not sure whether they are copied to the .dat file, and whether SumatraPDF will still write to the .txt file if it exists.