I've got this kind of issue for other apps I have tried to add even though gslapt said they were installed...my most specific example I can recall is with ruby ripper, I'd heard good things about it, added the dependences I could via gslapt and when trying to install the check said they weren't present. Same thing when I was trying to add VLC
I'm just saying I had the same problem although not with Audacity.
Does any one have suggestions to make installs more consistent and successful?