If you're using Daemon Tools or Alcohol 120% that's the problem. Specifically the problem seems to be that the sptd.sys driver is incompatible with macdrive. If you're using daemon347 you can just delete the sptd.sys file and both will work. If you're using daemon tools 4 or alcohol you need to uninstall them and delete the sptd.sys file because they require the file to work. Check out the following links: http://www.daemon-tools.cc/dtcc/t6992-how-...n-tools-v4.html and http://www2.daemon-tools.cc/dtcc/t6828-my-...th-sptdsys.html This second link is useful even if you're using alcohol 120%.