Hey there.
This has been a persisting problem for me; whether I hit the "Insert Image" button or use the "Manage Attachments" page, I cannot upload any maps or images to my posts.
The upload process itself seems to work. I use Google Chrome, and a blue bar with the words "Uploading: x%" comes up for both these options. But, after it makes it to 100% and goes away, nothing is changed. With the insert button, nothing appears in the post, and with the manage attachment page, no new attachments show up in my roster.
Is this a problem on my end? I can't imagine many others have experiencing this, since maps are posted every day.
Or perhaps I just have to wait an hour before the file is ready to be inserted? Dunno.