[OS X TeX] Undoing linkback

[Chris Goedde]

This was asked by someone on the Omnigraffle forums, with no answer.  
I'd like to know the answer too, so I thought I'd ask here.

The short question is: How do you break the linkback link between  
LaTeXiT and a pdf and reset LaTeXiT so that it creates a new pdf  
rather than modifies an existing pdf?

Longer: If I drop a pdf made with LaTeXiT onto Omnigraffle, I can  
establish a linkback connection by double-clicking the pdf. That's  
great if I later want to change the pdf. However, if I accidentally  
double-click (for example) the linkback link prevents me from making  
new pdfs because any changes I make in LaTeXiT change the first pdf.  
How do I break the connection and let LaTeXiT know I want to create a  
new pdf rather than modify an existing pdf?

Alternatively, how do I disable linkback altogether?

Chris