Just out of interest, I did some quick tests using Windows 7's resource monitor. This is on a 64-bit system with 8Gb. The results were:

Before running Vue, memory usage was 1318Mb used, 6730 free

When Vue was run the respective figures were: 1465 used, 6582 free, with 88% resources free according to Vue.

I created a single standard terrain, enlarged it to the size of the world grid, loaded the 'Cold Mountain' eco and reduced the scale of all the objects in the eco. Vue gave its standard warning that this might fail due to a lack of memory. I said do it anyway and got memory usage figures of 2897Mb used, 5028 free, and 78% resources free according to Vue.

Deleting the terrain gave figures of 2724 used, 5212 free, 79% resources free - some difference but not much.

Purge memory had no discernible effect. Closing the scene and opening a new default one gave figures of 2629 used, 5377 free, 81% resources free.

Closing Vue allowed Win7 to reclaim all the memory used.

Now, I don't know if this is a memory leak or what, but it's not very good if closing a scene doesn't automatically release all the resources the app used in that scene.

I haven't tried the plant editor - I'll give it a go when I have a moment if no-one else does it before then.

Steve