I can't post pics any longer either, and nothing changed here. check the size is what they told me, and be sure it's within the posting sizes, and resize before posting. I think it's like 480x600 or something like that?
The other option is doing what I've done. I put them on my free Photobucket account, then copy the image link and paste it in my post here.
The simplest thing with Windows 7 is to open the photos in Paint and reduce them until they are 500x800 or less. Do the 'Save as' (re-name it so the original on your computer stays large) and use a name that is different from the original name. I sometimes just add a number to the end (before the '.jpg') and you're good.
Then grabbing the photo is the same - go to the 'Go Advanced' tab and manage the attachment.
If you store your photos on a sharing site you can just grab the url for the photo and insert it directly into the body of the post.
The site was changed a while ago and the new people limited the size.