error input .PSB file

Hi,

I'am testing krpano 1.18.2, I tried to enter a file .PSB into droplet tool multires VTOUR, the messge was:

"INPUT ERROR: UNSUPPRTED IMAGE: HABANA.PSB ONLY FLATTEN PSD/PSB FILES ARE SUPPORTED"

Habana.PSB is a photoshop 6 .PSB file (without layer).... What is wrong?
(Image 29999x12875px, 290MB)

Thanks in advanced

Fernando
Fernando.

Thanks very much Klaus, I tried with "save without layer" instead to "flatten imagen". (I lost in spanish cs6 photoshop layer menu, the traslation of flatten imagen is "acoplar imagen")

Now works perfect, Krpano is great!

Greets,

Fernando