I'm not sure if a reinstall overwrites the DWMX pref file in your account pref folder. Save your current prefs to the desktop and delete the DWMX prefs in the account prefs folder. Relaunch DW and see if that helps any. This helped me recently with a sudden DW slowdown on OSX. If yes then put your old prefs back in (they contain all your site info) and export your site files to .ste. Retrash your prefs and relaunch DMW on a fresh pref file (import site files from previus pref set).
See if it works