problem with gif thumbnails

Hello everybody

I'm trying to scale and crop GIF image and I've got some strange problem -
white or black strip on the left side of the scaled image.

Examples you can see at
[full size image] - http://out.com.ua/storage/full_size.gif
[scaled image] - http://out.com.ua/storage/resized.gif

ImageMagick version is 5.5.7-Q8
JMagick version is 5.5.7-Q8

code for scaling and croping using JMagick API:
scaledImage = image.zoomImage((int) imageWidth, (int) imageHeight);
cropedImage = scaledImage.cropImage(new Rectangle(x, y, width, height));

any suggestions are welcome

-- 
Best regards,
Polzunov Sergei
e-mail: [email protected]
ICQ: #204206246