I'm assuming your existing backup is probably OK, it's just the restore process that went wrong, probably due to the broweser characteristics.
Having said that, the backup process is also fraught with issues. If you use the default backup to desktop function and your backup file is bigger than 2Gb you will most likely have problems both saving it and restoring it.
ALWAYS run the "Verify backup file" routine after doing a backup, to ensure your backup is a good one.
If your backup file is going to be bigger than 2Gb you need to use the backup2ws contrib (or others), and split the file to less than 2Gb pieces, that way the whole backup and restore process will work OK satisfactorily.