Thanks for the work-arounds, next time I run into the problem I'll try saving it from another machine to see what it does. We should also have a copy of AC12 kicking about somewhere as a fallback.
As for the textures, I had suspected them, and what has been said about them being saved in binary makes sense - although I'm fairly certain that my 40Mo cube saved from the 3D window was with a default material, and 100% certain that the SAME cube, saved from 2D, gave a 8Ko file (among other examples).
And if I understand the answers here, the problem doesn't seem to occur in AC14, and certainly didn't in AC11.
Which takes me on to a similar problem, although this time I have a work-around ;
When saving a module directly from the floor-plan (apologies if the terminology isn't quite correct - I've only ever worked in France) the file size is in the tens of Mo. The same elements (a couple of low-res jpegs a few lines and some text) saved from a "copy" ends up with a file in the low Ko's.
We opened both modules and they both have exactly the same contents.
As I said, we have an easy work-around by saving from a "copy" so it doesn't block us the way the 3D window, which is sometimes neccesary for certain more complex objects, does. It does seem that in AC13 depending on where you save it from, the same information can vary greatly in size.
We have only upgraded to AC13 recently, and while we find many aspects much improved, the problem with huge objects will oblige us to fall back on older versions for more more complex buildings we do, unless that is the work-arounds mentioned help us. I can think of at least a couple of recent projects that just wouldn't have been possible with AC13 because of this problem, which is rather unfortunate.
In any case, thanks for your answers and your time.
