Numbered step misaligned when inline graphic is included.

I'm not sure if my issue is with XMetaL, DITA, or the program we use to generate .pdfs from our XML.

I am using XMetal Author Enterprise, Version#: 5.5.0.219.

When I include a small graphic of a button inline with a step, the step number aligns with the top of the graphic, while the step text aligns with the bottom of the graphic. A sample is attached.

My question: can I control this alignment in DITA, or does it depend on how Publication Manager produces the pdf? I would like both the step number and text step to align with the bottom of the graphic.