5
rkennett,
1) i suggest to change your host.
2) upload zipped. Most hosting provider has got a panel with "extract" zipped files.
3) check if your host isn't compromised. Maybe someone get access there & joking with u.
4) if you're using a freeserver, check restrictions policy. An index.php must be appear anyway.
5)An URL & any extra data could help u better

Hope it helps, time for beer !