Attachments 'in progress' ?

Take a look at this reply:

https://www.wilderssecurity.com/showthread.php?p=348680#post348680

Basically, an "attachment in progress" error occurs when you have already upload the file in question in another window, but haven't yet submitted the post it's contained in. It can happen when a person has multiple posting windows open at the same time or when they've started a post reply with an attachment, and then start it again in a new window without backing out the previous attempted post.

I was able to manually attach the two in progess files to the post you tried to upload them into.