Getting Fonts Used in a PSD

I'm trying to script some font swapping in PSDs. It mostly works but I discovered a situation where it breaks. If multiples fonts are used on a single text layer, only the first font is listed. I don't know if there is a workaround for this. I've not found one thus far.

Here's the code I'm using, which I borrowed from a list archive somewhere:

tell application "Adobe Photoshop CS5"

     tell the current document

          set Used_Fonts to {}

          set Text_Layers to every art layer whose kind is text layer

          repeat with This_Layer in Text_Layers

               set This_Font to font of text object of This_Layer

               if This_Font is not in Used_Fonts then

                    set end of Used_Fonts to This_Font

              end if

          end repeat

     end tell

end tell

Used_Fonts

Thanks in advance for any insight into another method to get this info.

Stephan