Convert command throwing "UNEXPECTED" error

[seeno]

Hi everyone,
i'm trying to crop a part of djvu image using convert command, but its throwing error like this.
COMMAND: convert 0029.djvu -crop 150x150+100+100 xyz.png.
ERROR: "Unexpected". (ONLY)
the width and height of the djvu image is 2311 and 3529.
please reply ASAP

[dlemstra]

Can you post the version of ImageMagick and your operating system? It will also help if you post your djvu file om something like dropbox and add a link here.