--- a/suite/common/dataman/dataman.xul
+++ b/suite/common/dataman/dataman.xul
@@ -296,16 +296,17 @@
             <button id="cookieRemove"
                     label="&cookies.button.remove.label;"
                     accesskey="&cookies.button.remove.accesskey;"
                     disabled="true"
                     oncommand="gCookies.delete();"/>
             <checkbox id="cookieBlockOnRemove"
                       label="&cookies.blockOnRemove.label;"
                       accesskey="&cookies.blockOnRemove.accesskey;"
+                      flex="1"
                       persist="checked"/>
           </hbox>
         </vbox>
 
         <vbox id="permissionsPanel">
           <richlistbox id="permList" flex="1"
                        onkeypress="if (this.selectedItem)
                                      this.selectedItem.handleKeyPress(event);"/>