I've recently begun using Instagram as my primary photo app, but I've been having trouble tagging Twitter friends when I hit "Share Photo" > "Twitter" from within the app.
By default, Instagram autofills the Tweet field with whatever I've written for the photo caption. Very often, these captions include an "@ tag" or two -- basically just Twitter handles that I remember from memory. Sometimes they are activated as Instagram user names, but very often they are not. No matter what, the name is fully written and prepended with an "@" within Instagram -- What I see is what I get within the app.
But then when I share on Twitter, very often the "@" disappears. My friends aren't tagged when I tweet.
I understand this has something to do with Instagram's auto-detection of Instagram user names. But how can I ensure that What I see is What I get when I share an Instagram via Twitter?