Vista permissions for volume names vs drive letters

I was happily surprised that explorer.exe has support for volume names
now, in addition to drive letters, so I can browse my USB device by
going to a path like this:

\\?\Volume{d85a0f5e-ab4e-11dd-bdae-0050bfa331b4}\

As well as D:\.

The problem is, anytime I try to run an EXE I get a "permission
denied" type error, I don't have the exact error text handy, but it is
the same one I get when I try to rename a file I don't have write
access to. I can open JPG files in the same folder, and INI files,
but double-clicking any EXEs gives that error, and it isn't just EXEs
because I have an autorun.inf file in that folder also and I get the
same error when I try to open it (it normally opens in notepad, I
would think, like INI files do).

If I go to the drive via D:\, I can run the EXEs and everything works
fine. I get the same behavior in the run box:

\\?\Volume{d85a0f5e-ab4e-11dd-bdae-0050bfa331b4}\install.exe --
doesn't work

d:\install.exe -- works

On XP both work fine.

The reason it is a problem is I have an application which needs to
access the drives even when they don't have a drive letter assigned,
and it needs to run a program located on the drive.

Any thoughts? Just a new "lock down" in Vista that I can't easily get
around? I'd like a solution that wouldn't require elevation or admin
rights, so I don't think AddVolumeMountPoint is an option, to add a
mount point and then remove it when done.