Unfortunately I do not know of any way to resolve this particular reason for the Vista animation appearing, anything that I have read from MS during the Windows 7 development, has always ended with the "This is by design - will not be fixed" answer
There is another cause of this, for which, the solution has been well documented, both here and at other sites, but as our animation works with one display and not the other I do not believe this is the cause, in your case
For reference this fix is ....
Run an administrator command prompt and enter (without the quotes)
"bcdboot c:\windows /l en-us"
As an alternative There is this application which may allow you to get something more appropriate for your system - I've not checked this out so cannot state that it will work but maybe worth a try Change Windows 7 Boot Animation with Boot BMP Changer