Ubuntu Security :: Wipe With Ex4 Journaling File System?

I was reading a website about securely wiping data from your hard drive with wipe on the right click menu, when I stumbled across part of the article where it talked about journaling filesystems.Article

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There are three types of journaling: journal, ordered and writeback. Using shred, with an ext3 file system presents the user with the problem of secure deletion because it can only really be effectively used with ordered and writeback journals. It also lists ext4 as a journaling file system in the article, so I looked up the wikipedia page on it and I also found this:

Delayed allocationExt4 uses a filesystem performance technique called allocate-on-flush, also known as delayed allocation. It consists of delaying block allocation until the data is going to be written to the disk, unlike some other file systems, which may allocate the necessary blocks before that step. This improves performance and reduces fragmentation by improving block allocation decisions based on the actual file size. So I am confused about this delayed allocation thing. My thoughts are that ext3 and other journaling filesystems are bad to use with secure wipe when they are set on journal mode because that writes the file to the journaling sector as well as to the hard drive. Apparently, in ext3, the default was ordered mode. I would like to know if anyone has any idea if the ext4 file system on karmic 64bit is hazardous to the security of using the wipe command.