nextDirectory failing at 65535

I have a tiff stack of > 65535 images. Doing the following fails at n = 65535, where frames is the number of images which is significantly greater than 2^16.

    img_stack = Tiff( 'FILENAME.tif' ) ;
    [ i , j ] = size( img_stack.read() );
    img = zeros( i , j , frames) ;
    for n = 1 : frames
        img_stack.nextDirectory()
        img( : , : , n ) = img_stack.read() ;
        SOME PROCESS ON img  
    end

This fails with,

    Error using tifflib
    Unable to read the next directory.
    Error in Tiff/nextDirectory (line 934)
        tifflib('readDirectory',obj.FileID)
    Error in readin (line 5)
        img_stack.nextDirectory()

Then if we start the for loop at 65535 the loop fails at ... 2 * 65535! Given this is one integer below 2^16 suggests that the integer being used to keep track of nextDirectory() is a 16 bit number...?

Is this something anyone has come accross and knows more?

[DGM]

As far as I know, that's a limitation of tifflib.

If you can manage to get it to read the next 65535 frames by using an offset, then that would probably be decent workaround. I didn't expect that would work, but if it does, then that's in your favor.