Define a default placement option

Question

Hi everyone, I've created a dropdown in Flash Catalyst that needs to have its images updated once a week. That's easy enough to do because there's a handy option in Flash Catalyst to "edit images in Illustrator"
Once in Illustrator, I can then simply relink those images and save and it updates in Catalyst. Happy days.
However, the relinked images have to maintain the same dimensions as the image they are replacing, otherwise slightly different sized thumbnails will give a really horrid look overall, and will also defeat the beauty of relinking files.
In the Cs3 and Cs4 versions of illustrator there was a tick-box in the preferences which allowed you 'to preserve re-linked image dimensions' or something similar.
Because Adobe like to keep us on our toes, they have swapped it all around in Cs5, and this lovely, logical tick box has vanished! The nearest function I can find in the Cs5 version of Illustrator to the 'preserve re-linked image dimensions' is an option called 'image placement' which is located in the "links" window's flyout menu.
If I click on 'image placement' and select 'preserve bounds' the replacement image has the same dimensions as before, and that is what I want. Even if I relink to an image the size of the sun, it constrains it down to a nice 15ptx23pt thumbnail type image.
However, I have to set the 'image placement' to 'preserve bounds' whenever I relink for EVERY SINGLE IMAGE. Even though there's over a hundred images (it's quite a complicated drop down) I could live with switching every single image to 'preserve bounds' when relinked. Sadly, however, these 'image placement' settings get wiped every time I save what I've done in illlustrator and open up again to update from flash catalyst.
Honestly ridiculous, if Catalyst could be integrated with cs3 or cs2 I'd downgrade like a shot. But I can't (or can I?) so I'm stuck with the cs5 Illustrator, which is bling but can't do a thing. Well, not the ONE thing I want it to do anyway.
I know I've rambled. What I'm asking is: "How can I define a placement option, and set it to preserve bounds as a default?"

Answer 1

"In the Cs3 and Cs4 versions of illustrator there was a tick-box in the preferences which allowed you 'to preserve re-linked image dimensions' or something similar."
Are you sure that this was in Illustrator?
I rarely (almost never) used AI CS3 and 4, but I don't think that option was there. It's in InDesign, though.
Regarding the Image Placement options inside the Links palette: That always was kind of a poorly conceived effort which has never been really improved (I think it's there since AI 9 or 10).
Good luck.