The increase in safe download modes is more probably has to do with the hosts uploading the files. You downloads hang because Xolox is still trying to work out the last peice of the file, which is where the most file problems build up. (It is often at the end of a file that the most frequently changed data is stored; therefore, making it hard for Xolox to find an end that fits what it already has.) Additionally hosts sometimes will dissconnect before Xolox has become satisfied with the file (automatically closing when transfers are complete)