Strange, it works fine for me:
Excel 2007
<TABLE style="BORDER-BOTTOM: #a6aab6 1px solid; BORDER-LEFT: #a6aab6 1px solid; BACKGROUND-COLOR: #ffffff; BORDER-COLLAPSE: collapse; BORDER-TOP: #a6aab6 1px solid; BORDER-RIGHT: #a6aab6 1px solid" rules=all cellPadding=2><COLGROUP><COL style="BACKGROUND-COLOR: #e0e0f0" width=25><COL><COL><COL><COL><COL><COL></COLGROUP><THEAD><TR style="TEXT-ALIGN: center; BACKGROUND-COLOR: #e0e0f0; COLOR: #161120"><TH></TH><TH>A</TH><TH>B</TH><TH>C</TH><TH>D</TH><TH>E</TH><TH>F</TH></TR></THEAD><TBODY><TR><TD style="TEXT-ALIGN: center; COLOR: #161120">1</TD><TD>Date</TD><TD>OrderID</TD><TD>Shipped</TD><TD style="TEXT-ALIGN: right"></TD><TD>Count:</TD><TD style="TEXT-ALIGN: right">1</TD></TR><TR><TD style="TEXT-ALIGN: center; COLOR: #161120">2</TD><TD style="TEXT-ALIGN: right">5/19/2011</TD><TD>123ABC</TD><TD>qwe123</TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD></TR><TR><TD style="TEXT-ALIGN: center; COLOR: #161120">3</TD><TD style="TEXT-ALIGN: right">5/20/2011</TD><TD>456ABC</TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD></TR><TR><TD style="TEXT-ALIGN: center; COLOR: #161120">4</TD><TD style="TEXT-ALIGN: right">5/20/2011</TD><TD>789ABC</TD><TD>asd123</TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD></TR><TR><TD style="TEXT-ALIGN: center; COLOR: #161120">5</TD><TD style="TEXT-ALIGN: right">5/20/2011</TD><TD>123DEF</TD><TD>zxc987</TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD></TR></TBODY></TABLE>
<TABLE style="BORDER-BOTTOM: #a6aab6 1px solid; BORDER-LEFT: #a6aab6 1px solid; BACKGROUND-COLOR: #ffffff; BORDER-COLLAPSE: collapse; BORDER-TOP: #a6aab6 1px solid; BORDER-RIGHT: #a6aab6 1px solid" rules=all cellPadding=2><THEAD><TR style="TEXT-ALIGN: center; BACKGROUND-COLOR: #e0e0f0; COLOR: #161120"><TH>Sheet1</TH></TR></TD></THEAD><TBODY></TBODY></TABLE>
<TABLE style="BORDER-BOTTOM: black 2px solid; BORDER-LEFT: black 2px solid; PADDING-BOTTOM: 0.4em; BACKGROUND-COLOR: #ffffff; PADDING-LEFT: 0.4em; PADDING-RIGHT: 0.4em; BORDER-COLLAPSE: collapse; BORDER-TOP: black 2px solid; BORDER-RIGHT: black 2px solid; PADDING-TOP: 0.4em" rules=all cellPadding=2 width="85%"><TBODY><TR><TD style="PADDING-BOTTOM: 6px; PADDING-LEFT: 6px; PADDING-RIGHT: 6px; PADDING-TOP: 6px">Worksheet Formulas<TABLE style="BORDER-BOTTOM: #a6aab6 1px solid; TEXT-ALIGN: center; BORDER-LEFT: #a6aab6 1px solid; BACKGROUND-COLOR: #ffffff; BORDER-COLLAPSE: collapse; BORDER-TOP: #a6aab6 1px solid; BORDER-RIGHT: #a6aab6 1px solid" rules=all cellPadding=2 width="100%"><THEAD><TR style="BACKGROUND-COLOR: #e0e0f0; COLOR: #161120"><TH width=10>Cell</TH><TH style="TEXT-ALIGN: left; PADDING-LEFT: 5px">Formula</TH></TR></THEAD><TBODY><TR><TH style="BACKGROUND-COLOR: #e0e0f0; COLOR: #161120" width=10>F1</TH><TD style="TEXT-ALIGN: left">=COUNTIFS(C:C,"=",B:B,"<>")</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>
See if this alternative gives you the desired value:
<b>Excel 2007</b><table cellpadding="2.5px" rules="all" style=";background-color: #FFFFFF;border: 1px solid;border-collapse: collapse; border-color: #A6AAB6"><colgroup><col width="25px" style="background-color: #E0E0F0" /><col /><col /><col /><col /><col /><col /></colgroup><thead><tr style=" background-color: #E0E0F0;text-align: center;color: #161120"><th></th><th>A</th><th>B</th><th>C</th><th>D</th><th>E</th><th>F</th></tr></thead><tbody><tr ><td style="color: #161120;text-align: center;">1</td><td style=";">Date</td><td style=";">OrderID</td><td style=";">Shipped</td><td style="text-align: right;;"></td><td style=";">Count:</td><td style="text-align: right;;">1</td></tr><tr ><td style="color: #161120;text-align: center;">2</td><td style="text-align: right;;">5/19/2011</td><td style=";">123ABC</td><td style=";">qwe123</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">3</td><td style="text-align: right;;">5/20/2011</td><td style=";">456ABC</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">4</td><td style="text-align: right;;">5/20/2011</td><td style=";">789ABC</td><td style=";">asd123</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">5</td><td style="text-align: right;;">5/20/2011</td><td style=";">123DEF</td><td style=";">zxc987</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr></tbody></table><table cellpadding="2.5px" rules="all" style=";background-color: #FFFFFF;border: 1px solid;border-collapse: collapse; border-color: #A6AAB6"><thead><tr style="background-color: #E0E0F0;text-align: center;color: #161120"><th><b>Sheet1</b></th></tr></td></thead></table><br /><br /><table width="85%" cellpadding="2.5px" rules="all" style=";border: 2px solid black;border-collapse:collapse;padding: 0.4em;background-color: #FFFFFF" ><tr><td style="padding:6px" ><b>Worksheet Formulas</b><table cellpadding="2.5px" width="100%" rules="all" style="border: 1px solid;text-align:center;background-color: #FFFFFF;border-collapse: collapse; border-color: #A6AAB6"><thead><tr style=" background-color: #E0E0F0;color: #161120"><th width="10px">Cell</th><th style="text-align:left;padding-left:5px;">Formula</th></tr></thead><tbody><tr><th width="10px" style=" background-color: #E0E0F0;color: #161120">F1</th><td style="text-align:left">=SUMPRODUCT(<font color="Blue">--(<font color="Red">B2:B5<>""</font>),--(<font color="Red">C2:C5=""</font>)</font>)</td></tr></tbody></table></td></tr></table><br />