Is the DB is simple, full, or bulk-logged mode?

If in bulk or full mode make certain you have transaction log backups running. The "standard" is typically every 15 minutes however, depending on your environment that may be too soon (the general rule of thumb is "how much data are you comfortable with losing?" :-D)

For more information on the Transaction Log, what it is, how it works, etc - Please refer to this excellent article[/url] by the Master, Gail Shaw

BTW everything is written/committed in the transaction log