Re-read this section of the Furniture tutorial; you need to 'set' the size/scale of the object before you export (and before you parent - which means you'll need to unparent the mesh,
"Alt+P" select "Keep Transform", then follow the instructions cited).
If the item is blank in IMVU it means you've not assigned your vertex group properly (there isn't one or there's a 'problem' of some kind). Again it says in the tutorials that you need to make sure to have your initial group called "
Root" - if you don't do this IMVU won't know what to do with the mesh which is why it doesn't display.
You may also need to properly name your materials so you have at least "
Material[0]" etc., instead of "
Material.001", this will produce "
Material[0].xrf" (good) instead of "
Material.001.xrf" (bad) which can be problematic for IMVU to understand (your actual texture images can be called anything you like, it's the material names that are important).
By the way if you have multiple posts you can edit your previous and just add the new info to that, just saves having to scroll through pages of posts with little information.