Web app referencing 32-bit dll on 64-bit OS

I have a web app that I am trying to deploy on a Windows 2003 x64 OS on a
dedicated server at 1 and 1. I am having trouble referencing one of the required
3rd party dlls. I get the following error:

Retrieving the COM class factory for component with CLSID
 failed due to the following error:
80040154

 Everything I have read points to the fact that this is a 32-bit dll on a 64-bit
server. I have set IIS to run in worker proces isolation mode and
Enable32bitApponWin64 set to "true". What else do I need to do to get
this to work? Any help would be greatly appreciated!

Some components just will not work on a 64-bit machine, regardless of what mode
you have IIS set in.  But, some will.  You may need to talk to the vendor to see
if they know if it will work.

Did you reboot your server after setting Enable32bitApponWin64 to true?  IIRC a
reboot is required for it to take effect.

Yes, I did reboot the server - it didn't help. I have contacted the vendor and
they have successfully tested the dll on a 64-bit server. Mind you, they tested
it with a 32-bit application, not a web application. So, the issue at hand is
how to get his website to run as 32-bit. Everything I have read tells me that I
need to compile it with x86 as the target platform. Problem is, that is not an
option in a "website". So I guess I need to convert this project to a
"web application". Not sure how I can do that without completely
rebuilding it from scratch, and that would be a major undertaking.

You can see if your site is running 32-bit by checking task manager.  Look for
the w3wp.exe processes.  They will have something like *32 beside them.  (I
don't remember the exact syntax).  Another thing to check is your file mappings
for .aspx and other .NET extensions.  It's behind the "Configure"
button in the "Home Directory" tab in IIS Manager.  Make sure that
they are pointing to c:\windows\microsoft.net\framework instead of
c:\windows\microsoft.net\framework64.

If it's running 32-bit, then I think it's going to be the same as running from a
32-bit application.  In that case it sounds like the vendor thinks that it
should work and no ideas stand out to me.  So, the first thing I would recommend
is to confirm that your sites really are running in 32-bit mode.

It sounds to me like the Enable32bitApponWin64 setting didn't take.  The fix
might be quiet easy then since the problem is with a well documented setting,
and not with a 3rd party dll running from a web application.

I suggest reviewing your Enable32bitApponWin64 setting and see if you can find
something that was set wrong.  You can view your metabase.xml file directly and
search for that and see if it's set to true.