I'm not part of the staff, but I have experience with this issue. Sometimes it's caused by faulty/outdated scripts being run on the server, which tends to happen a lot on free hosting with its multitudes of (no offense to anyone, just being realistic) frequently novice or inexperienced users. The resulting errors are all logged and the logfiles themselves, something intended to help diagnose problems, cause the problem. Error logs in excess of a gigabyte have been found, like electronic cysts or tumors on servers.
Sometimes it's caused by, or compounded by, what is known as memory leakage. This is when processes run that can't be terminated, like turning on a tv, changing channels, and the other channel not going away, or something. These processes sometimes loop infinitely, and can only be stopped by restarting the server, whereupon they begin again as soon as someone visits the site with the faulty scripts. This in turn often bloats the error logs, making it even worse.
The only solution, aside from occasional rebooting and deletion of morbidly obese logfiles is to use scripts and applications on your site that are, to use building parlance, up to code.
Sorry I can't do anything to fix your problem, but I hope the information can be of some use somehow.