@Tamras
Actually, just looked at a couple things here. Not sure if this is completely accurate at this point as I need to investigate more...
The main reason that I used to pull the Attachment control out of a Form was twofold:
1) The Attachment control used to be on the Insert Controls list...it was removed some time ago.
2) I liked that control because it would open a File Dialog with "*.* All Files" as the file type. Using an Add Picture control was an option, but it always opened the File Dialog with "Picture" as the file type...very annoying if you are dealing with a bunch of Doc or PDF files.
So, if I pulled the Attachment control out of the form and stood it on its own, it would give me the support to get the File Dialog that I wanted.
To cut to the chase - I just looked at a sample App that I put together that used this perfectly. In that app I had also put the Add Picture control for contrast in testing. I just clicked on it and it brought up a Dialog with "*.* All Files". What??? Went into another app and threw an Add Pictures Control and same thing!!
So, either there is a new bug with the Add Picture control, or they changed it to allow all files to be the default. But, technically at this point...I would ditch the attachment control all together in favor of the Add Picture control.
Just thought I might add that to your thoughts.