“apec1.jpg” has failed to upload due to an error The uploaded file could not be

Hi i need help when try to upload image the message coming “apec1.jpg” has failed to upload due to an error The uploaded file could not be moved to /home/indonXXXX/public_html/wp-content/uploads/2012/09.
for your information i have subdomain/subdirectory too, and dont have problem with that,before. thank you for your help