wp-touch has no problems with shorter posts (shorter then about 50 rows).
is the post longer, the following problem occurs:
Once you have savex the post, the richt text editor disappears and you can't switch back. after saving you can only use html-mode and even this mode comes with white text on white background, so must mark the text to see it.
after deactivating wp-touch the problem disappears and you can edit the post in your desired mode!