Do You Use The NotesXSLTransformer Class?

If so be aware because if you use <xsl:sort> in your stylesheet the result may not be correct.
IBM Support:

I would like to let you know that I was able to reproduce this PMR issue.
I have now created SPR (Software Problem Report): KMUR6K8JAZ, APAR: L011758
This issue will be fixed in a further release.

This wrong sort order result is in Notes/Domino 6 and 7.