My wordpress adminstrator says some plug-ins attempt to modify the htaccess file which sometimes results in this. basically i was getting a blank screen when i tried to access any of the pages. he renamed the social crowd plugin folder to social crowd.anything and its gets deactivated. then you can delete the plugin from the dashboard.
that’s all i know. i really liked the look of this plugin and its customization options and hope it gets fixed soon. i’ll be using some other social plugin now of course.