I downloaded the latest cvs version. I made own content type with imagefield, after that i'm going to create some node, using fresh created type, i got the first warning:
Warning: Invalid argument supplied for foreach() in /home/mephir/cvs/image_fupload-HEAD/image_fupload_imagefield/image_fupload_imagefield.module on line 533
Ok, let's go far. I correct this warning with adding id statement which checks $fields_to_remove if it is array, warning dissapered. Ok next chance, we are adding title, body and images. Ops in images i have default type "*."(sometimes "*.;*."). Ok it isn't so terrible, so i use direct swfupload settings change by Firebug:
SWFUpload.instances['SWFUpload_0'].setFileTypes('*.jpg;*.png;*.gif','Web images');
Now i can select images ;) so i click "save" and "next step", so i got another php warning:
Invalid argument supplied for foreach() in /home/mephir/cvs/image_fupload-HEAD/includes/images.previewlist.imagefield.inc on line 24 So i made another temporary fix(without getting sence of code, only simple $field_image['widget']['fupload_previewlist_field_settings']=array(); before foreach ....).

I think, these warnings could be more ... I try to make compatible ckeditor module and image fupload, but i waste my time for correct your code.