I have also tried this but I can't get it to work.
It does not matter if I scale or decrese point size, only the text shown in the frame gets affected. So I end up with a text that is unevenly sized over its length... :S

This is what I do:
tell myTframe
set scale to 100
repeat until overflows is false
set scale to scale - 1
set horizontal scale of text of myTframe to scale
set vertical scale of text of myTframe to scale
end repeat
end tell
I have also tried to set the scale to every character of ....
but no luck...

Any suggestions on how to solve this?