(For the record: I am running Windows 7 64 bit and this worksd for me. sometimes there is a slight delay, but it is really the only simple way to have a Start Menu button in ObjectDock.)
The first thing you need to do is create a text file called "SendKeys.vbs" (without the quotes, obviously). This will be a simple VB file.
Put the single line below in that file and save it in your %SystemRoot%, i.e. C:\Windows directory.
CreateObject("WScript.Shell").SendKeys Wscript.Arguments(0)
Next, create a text file called "Startmenu.bat" (again, without the quotes). This is a basic batch file.
Put the single line below in that file and save it in your %SystemRoot%, i.e. C:\Windows directory.
start /w Sendkeys.vbs "^{ESC}"
Go to your Dock and 'Add a New Shortcut".
Make the shortcut link to the "Startmenu.bat" file.
Set the link to run minimized. This is for aesthetic reasons. You won't have to see the dos box pop up and then dissappear and wonder what it was.
Set your icon to be the StartMenu icon provided by Stardock or put your own icon that you wish in as the icon.
Click on your new Start Menu button and if it works for you, let me know.
Thanks for reading and I hope this helps everyone!