I almost searched and tried every possible solutions in this error… also tried this http://wordpress.org/support/topic/162373#post-716574 and edit my .htaccess but nothing happens and still I got the same error. Also, I’ve tried this one installing the wordpress image upload error fix plugin still plugin not working for me…

Thanks for this great post and it really solved my problem. I just disable the flash uploader. Download the no flash uploader plugin and activate it in wp-admin under plugins and CHMOD to 755 the wp-content/uploads directory.  Thats it! I can upload my images now!