Bidvertiser are ok if you can deal with the amount of spam emails they send.
When I had an account with them I was getting over 10 emails a day. And that was with setting my email preferences to not to receive emails.
It's losing connection to the database server. Either the database server is crashing or its overloaded.
Take a look at /var/log/mysqld.log if you have access to it.
The leeching plugin, once completed, will allow you to download from several other file hosting sites.
It is not finished yet due to a lot of the sites not allowing http auth. So I am trying to figure out a work around. For those sites.
Check that the Apache Module ModRewrite is installed and working
Check that the .htaccess file is not corrupted, if in doubt, re-upload it.
Also if in doubt, re-upload file_download.php
I just downloaded the file both on my dev site and live site without problems.
If you're having Ajax/jQuery issues, try re-uploading the contents on the /js/ directory.