We apologize for the difficulty you may have experienced recently when trying to reach Tatoeba. We are about to move to a new server in order to address these problems permanently. The migration should be finished within the next two weeks. Thank you for your patience.
Update 1 (2014-07-30)
We have ordered a new server and it was delivered this morning. Gillux and saeb are currently working on it. We can't say for sure yet when Tatoeba will be back up, but we're progressing.
Update 2 (2014-07-31)
We are making progress, but yesterday afternoon we lost connection to our new server while trying to configure it. We have opened a ticket and are now waiting for our host to investigate the issue.
Update 3 (2014-07-31)
We have access again. At the moment, we're still configuring the server.
Update 4 (2014-08-02)
We're done installing everything. Huge thanks to gillux and saeb! We're testing things a bit to make sure that everything works properly, but Tatoeba should be back some time today :)