I hit "reply", "Post my message", and it just keeps saying "Please wait. Processing.." and never posts.

There are several reasons why a post might fail. Some character combinations are blocked as a spam prevention measure (I don't recall whether the block is still in place or how simplistic it is). If the tags are messed up, that might cause the post to not be posted. If the post is too long (10,000 characters, iirc), then it also won't post.

There might be some Galaxy specific reasons as well, but I don't use Galaxy and wouldn't know what (if any) those are.