Sometimes the connection to our server brakes and you don?t get the whole file!
Or did you backup your db onto your server if not do so and download the backup via FTP
If the db is still 300k maybe you have deleted yout search index and your adminlog (i do that for updates cause it makes them much smaler!)
Check your backupfile and look if the last table is words if so the file is complete!
Greetings
StarBuG