Styling titles of figures in sidebars

Hello,

I've customized the styling of sidebars to
   <xsl:template match="sidebar">
     <fo:float float="outside" start-indent="0pt" end-indent="0pt"  
clear="both">
       <fo:block-container width="150pt" padding="6pt" margin="4pt"  
font-size="10pt">
         <xsl:if test="./title">
           <fo:block font-weight="bold"
                 keep-with-next.within-column="always"
                 hyphenate="false">
             <xsl:apply-templates select="./title"  
mode="sidebar.title.mode"/>
           </fo:block>
         </xsl:if>
         <xsl:apply-templates/>
       </fo:block-container>
     </fo:float>
   </xsl:template>

Most importantly, I've reduced the font-size to 10pt. Now if I include a  
figure with a title into a sidebar that title has a much larger font-size.  
How could I reduce that font-size?

thanks and best regards
Steffen Glückselig