February 19, 2012, 11:08:50 pm
Couple of things also:
1. given the time on mucking around it might be quicker and long term better, if practical, to simply increase your RAM, get 2 4GB sticks, hardly cost much these days so would be worth it
2. reduce the texture resolutions you are using in your model, only keep high res ones for closeups, for example reducing a 2048x2048 to 512 x512 or maye 1024x1024 will make a big diff to available GPU memory. See Tips and Tricks FAQ, and there's a recent topic about reloading of textures and Lumion limits. Copy your source export folder for backup, then use an image tool to batch change all required textures to a lower res, should only take about 10 minutes and reload, there's no need to edit the textures in your DCC.
One other thing, if not currently doing so, but make sure you save your project with new names so you have some versioning, this might clean things up a little but also protect you if there's a real memory problem and the project gets saved in some corrupted form. Lumion seems very, very stable and good in this area so it's just for insurance purposes given the memory issues.