Ooh, that sounds bad! If the error is being thrown by libtiff3.dll, that
suggests that it simply doesn't support images of that size and,
unfortunately, there's not much I can directly do about that. However, you
could try seeing whether you can find a newer version of the the DLL that
might support it. As long as the interface hasn't changed you should just
be able to replace the DLL file (but make a back-up first!)
Failing that, I'd see if you could get any image processing program to load
it and cut it down into a few pieces. You should then be able to load them
in as a multiple stack and align the different sections correctly.
Let me know how it goes,
Darren