philfrominverell on "[Plugin: Po.st: The Social Sharing Platform that Generates Revenue for Your Website] cannot upload images to my website"

I have been unsuccessful in uploading images from my harddrive onto my website. For instance they seem to go into my media library but i cannot 'set featured image' for my home page slider or for boxes on the home page. they try to upload but i get an error message with no particular error number.
I have also tried to upload via ftp software but i'm not sure what folder to paste them into.

thanks

http://wordpress.org/extend/plugins/post/