With IE7 (Vista), an empty XML Block has an unneeded space so if you click in the editable zone you're text will always begin with a space. (I use the svn version of eZOE)

Steps to reproduce

With ezwebin
1. create (for instance) a new "blog post"
2. click in the editable zone
3. start typing your text

if you go to the start of the text, you will see a space.