Whenever I have a grouped TableView with enough content that it requires scrolling, I run into problems with the padding of the rows changing as they're scrolled in and out of view. The following image highlights the problem (notice the alignment of the bottom 4 rows):
http://img210.imageshack.us/img210/1198/centered.png

Full code to run the application is here (only about 90 lines):
http://pastie.org/1054419

Steps:

1. Scroll to the bottom of the window.
2. Scroll back to the top of the window.
3. Any rows that couldn't fit into the display when you did #2 will now be incorrectly aligned. (It helps if you scroll a little bit beyond the top, so that the view bounces back into place)

Note that this problem seems to be linked to using 'auto' for the row width. If you explicitly specify a width and leave out the 'right' padding for the row, it behaves fine. But then you can't support landscape view.

I am using 1.3.2 and iPhone SDK 4.0.