Conflict with ImageApi Optimize

Hi!

I love this module, so i use it on almost every site of mine. But i bumped into an error. Reproduced on a fresh D7: i've installed and configured Image Resize Filter and ImageAPI Optimize. Inserting an image (png, attached using file field) shows up correctly, but when i add width/height, after save i get this message, and the page won't load:

Status message
Basic page test has been updated.
Error message
Recoverable fatal error: Argument 1 passed to image_resize() must be an instance of stdClass, boolean given, called in /home/<thissite>/sites/all/modules/image_resize_filter/image_resize_filter.module on line 499 and defined in image_resize() (line 279 of /home/<thissite>/includes/image.inc).

When i switch back the image toolkit to default GD2, it's working.

Any help would be appreciated.

Frici