Running sigcheck on cobundle gives me following output:
C:\Sigcheck>sigcheck Z:\disk15\iteam\jdk-6u13-javafx-1_1_1-windows-i586.exe

sigcheck v1.60 - sigcheck
Copyright (C) 2004-2009 Mark Russinovich
Sysinternals - www.sysinternals.com

z:\disk15\iteam\jdk-6u13-javafx-1_1_1-windows-i586.exe:
        Verified: Signed
        Signing date: 4:59 AM 4/10/2009
        Strong Name: Unsigned
        Publisher: n/a
        Description: n/a
        Product: n/a
        Version: n/a
        File version: n/a

See there is no Manifest: xxx kind of entry.
There is a communication problem. The XXX part of the manifest is that long xml portion. Where it says "Manifest: ...." and there are 20 lines of text. see the blurb below, that shows it is both Signed and has a Manifest

sigcheck.exe -q -m y:\jdk-6u13-javafx-1_1_1-windows-i586.exe
y:\jdk-6u13-javafx-1_1_1-windows-i586.exe:
Verified: Signed
Signing date: 7:29 PM 4/9/2009
Publisher: n/a
Description: n/a
Product: n/a
Version: n/a
File version: n/a
Manifest:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
  <assemblyIdentity version="6.0.130.92"
     processorArchitecture="X86"
     name="jdk-6-windows-i586"
     type="win32"/>

  <description>Java(TM) SE Runtime Environment 6.0 Update 13</description>
  <!-- Identify the application security requirements. -->
  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
    <security>
      <requestedPrivileges>
        <requestedExecutionLevel
          level="requireAdministrator"
          uiAccess="false"/>
        </requestedPrivileges>
       </security>
  </trustInfo>
</assembly>