One or two XSLT/XPath bugs

Question

I have an XSLT problem that may actually be two problems. My stylesheet works as expected in MSXML and Xalan but does very weird things in Oracle's XSLT processor. Below is the stylesheet, followed by some test input. It looks like just one bug if you run it on this test input (the "extra rows" generated get numbered 10-14 rather than 20-24, but $count and $remainder seem to have the right values). If you delete all COWS after SEQNUM 13, however, then $count and $remainder are both wrong. So it may be one bug, may be two.
XSLT:
====================================================
<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
     <!-- output a CHICKENROW for each CHICKEN in the source document, and guarantee there's a positive multiple of 8 rows total -->
     <xsl:template match="/">
          <CHICKENROWS>
               <xsl:for-each select="/COWS/COW[KEY1 = '1']">
                    <CHICKENROW seqnum="{SEQNUM}">
                         <xsl:value-of select="CHICKEN"/>
                    </CHICKENROW>
               </xsl:for-each>
               <xsl:variable name="count" select="count(/COWS/COW[KEY1 = '1'])"/>
               <!-- uncomment this for debugging
               <count><xsl:value-of select="$count"/></count>
               -->
               <xsl:variable name="remainder" select="$count mod 8"/>
               <!-- uncomment this for debugging
               <remainder><xsl:value-of select="$remainder"/></remainder>
               -->
               <!-- if we have fewer than a positive multiple of 8 rows, add empty rows -->
               <xsl:if test="$count = 0 or $remainder &gt; 0">
                    <xsl:variable name="startSeqnum">
                         <xsl:choose>
                              <xsl:when test="/COWS/COW[KEY1 = '1']/SEQNUM">
                                   <xsl:for-each select="/COWS/COW[KEY1 = '1']/SEQNUM">
                                        <xsl:if test="not(/COWS/COW[KEY1 = '1' and SEQNUM &gt; current()])">
                                             <xsl:value-of select=". + 1"/>
                                        </xsl:if>
                                   </xsl:for-each>
                              </xsl:when>
                              <xsl:otherwise>
                                   <xsl:text>1</xsl:text>
                              </xsl:otherwise>
                         </xsl:choose>
                    </xsl:variable>
                    <!-- insert as many empty rows as necessary to guarantee we have at least 8 rows and the total # of rows is a multiple of 8 -->
                    <xsl:call-template name="emptyRows">
                         <xsl:with-param name="seqnum" select="$startSeqnum"/>
                         <xsl:with-param name="endSeqnum" select="$startSeqnum + (8 - $remainder) - 1"/>
                    </xsl:call-template>
               </xsl:if>
          </CHICKENROWS>
     </xsl:template>
     <!--
          Recursively insert empty rows with seqnums starting at $seqnum and going to $endSeqnum
     -->
     <xsl:template name="emptyRows">
          <xsl:param name="seqnum"/>
          <xsl:param name="endSeqnum"/>
          <xsl:if test="$seqnum &lt;= $endSeqnum">
               <CHICKENROW seqnum= "{$seqnum}"></CHICKENROW>
               <xsl:call-template name="emptyRows">
                    <xsl:with-param name="seqnum" select="$seqnum + 1"/>
                    <xsl:with-param name="endSeqnum" select="$endSeqnum"/>
               </xsl:call-template>
          </xsl:if>
     </xsl:template>
</xsl:stylesheet>
=======================================================
INPUT XML:
=======================================================
<COWS>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>1</SEQNUM>
          <CHICKEN>ACMI2</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>2</SEQNUM>
          <CHICKEN>ALTE</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>3</SEQNUM>
          <CHICKEN>ANRO2</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>4</SEQNUM>
          <CHICKEN>ARCO5</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>5</SEQNUM>
          <CHICKEN>ARFR4</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>6</SEQNUM>
          <CHICKEN>ARTRV</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>7</SEQNUM>
          <CHICKEN>ASMO7</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>8</SEQNUM>
          <CHICKEN>CAGE2</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>9</SEQNUM>
          <CHICKEN>COUM</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>10</SEQNUM>
          <CHICKEN>ERIOG</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>11</SEQNUM>
          <CHICKEN>FEID</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>12</SEQNUM>
          <CHICKEN>LEPID</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>13</SEQNUM>
          <CHICKEN>LEPID</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>14</SEQNUM>
          <CHICKEN>LEPID</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>15</SEQNUM>
          <CHICKEN>LEPID</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>16</SEQNUM>
          <CHICKEN>LEPID</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>17</SEQNUM>
          <CHICKEN>LEPID</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>18</SEQNUM>
          <CHICKEN>LEPID</CHICKEN>
     </COW>
     <COW>
          <KEY1>1</KEY1>
          <SEQNUM>19</SEQNUM>
          <CHICKEN>LEPID</CHICKEN>
     </COW>
</COWS>

Answer 1

... or maybe they're not bugs at all, but if they're not, they're at least a difference in implementation from MSXML and Xalan. Do I misunderstand the XPath/XSL I'm using here? Is Oracle's interpretation equally valid?