image upload error

Hi, my buddy is getting this error on his blog when he tries to upload an image – this has happened all of a sudden, he hasn’t had this problem before: ” Unable to create directory /home/.sinder/greenventures/thechinaobserver.com/wp-content/uploads/2009/02. Is its parent directory writable by the server?”

I checked using Filezilla to check the permissions, they all look fine… so what could the issue be?