I emailed the Nabble board today at 4:41pm to show my issue with a true type font symbol. It flips horizontally when called from the SLD.
I have tested by creating a flipped version of the TFF library and these symbols worked.
I am unsure if its because i am using the symbol attached to a Polygon Symbolizer or this problem applies to all.
Your example on the blog using Windings didnt seem to have the issue.
I have put this as a Major priority but not sure if it warrants that status.