replacing footage & keeping the dimensions

Hi,

this has been discussed before, but in case there's any news on the subject, i'll start this once again:

Is it possible to replace footage in a way the it would remain the same size in all the comps?

I've created a huge scene with complex animation for 1080p renders, and my source footage seems to be too big for AE to handleae_ and the rendering continuously stops to "can't create xxx image buffer" (which i think is unforgivable and ridicilous from a software like this, rendering for 8 hours over night and crashing to a memory error like this. And not automatically continuing from a frame it crashed on. Arrgh.)

I've set proxies to files which are really small in size (like 300x300px) and they work fine, keeping all the dimensions. So it should be possible to replace the footage keeping the dimensions, because proxies can do it. The only solution i've found so far is using my smaller files (which i wan't to use in the final render as well) as proxies and render the final videos with proxies. But then i lose the opportunity to use the proxies in their original purpose.

I think there should be a "keep originial dimensions" setting in the replace footage panel, if it's not already somewhere else. Anybody?

-ilmeri