Bug in XSL Stylesheets concerning relative image paths

A bug was introduced in stylesheets version 1.66 (html and fo, remains 
in version 1.67) concerning relative paths:

    <inlinegraphic  fileref="../../common/img.png"/>

becomes

    <img src="common/img.png"/>

All leading "parent directories" (../) are simply cut. In version 1.66 
relative paths in graphic environments remained untouched. My admonition 
and callout graphics are stored in "../../common/decorative/", however 
these paths are not mangled and work well.

I don't know where to fix this in the stylesheets, have I to switch back 
to 1.66?

Regards,
Georges Schmitz