MY TB DW's update the Blob column perfectly in XP when I type text into them, set the RichText properties and issue the DC.Update( ). I verified the updated RTF blob data in the DB using TOAD. Of course, I cannot test this in W7 as the RTE TB DW GPF's before I can get that far. :-(
FYI: The TB DW's also update image blobs correctly as well in my testing. In fact, I have no problems Retrieving and Updating with TB based DW's in XP W7 or W2008R2 when handling images. Its only the RTE aspect that goes "south" on me.