Small oddity in adding data frames in Append dialog

[rdstern]

@N-thony Here it is:

In the Prepare > Reshape > Append I might have this:

I can keep adding and that's fine. But if I Close (or press Ok) and then Reopen and add I get this:

Now I have checked briefy and think this may be the only dialog with this problem. If I have a multiple receiver and add more columns it seems fine. There are not many dialogs with multiple data frames and the other I found clear the receive on re-opening - and I am happy with that there. But I'd prefer not to clear on re-opening in Append.

I hope it will be trivial to fix.