Edit: Ok it looks like the "Enabled WM SMS Thread.cab" file in the installation section of the first post at:
http://forum.xda-developers.com/showthread.php?t=622520
seems to put it back to the standard layout.
Has anybody found how to disable the bubble SMS at that link above? All I can find is how to INSTALL the bubble format. I guess I'll keep reading, hopefully it's in there somewhere...